Build previews using dapp-development tagged packages

BACKGROUND:
There are situations when team developing T Token Dashboard needs to
locally test some functionalities using modified contracts, for example
ones with shorter authorization decrease delay. We decided to create a
`dapp-development` branch in each of the expected upstream modules of
the `threshold-network/token-dashboard` CI module, which would store
the code of these modified contracts. (Although currently there's no
`@keep-network/random-beacon`, `@keep-network/ecdsa` and
`@keep-network/tbtc-v2` dependencies in the T dashboard yet, they're
expected to be added soon and we are already preparing for that).
Repositories with `dapp-development` branch containing modified
contracts:
`threshold-network/solidity-contracts`
`keep-network/keep-core`
`keep-network/tbtc-v2`
Using the code from the `dapp-development` branch we will build
packages that will be published to the NPM registry under
`dapp-development-<environment>` tag and with `dappdev<environment>`
suffix (`<environment>` currently being `goerli`).
Generally, the goal of the changes is to have the full set of
dapp-development-friendly contracts deployed to the NPM registry, so
that they could be used to create dApp previews that will be easily
testable. The dApp developers could also use the contracts to build
dashboard on their local envirionment by upgrading the
`token-dashboard` dependencies using
`yarn upgrade <package-name>@dapp-development-goerli`.

THIS CHANGE:
In this commit/PR we modify the GH Actions job which is used for
publishing of the testnet dashboard to the main and preview testnet
buckets. We're splitting this job into two separate jobs:
- `build-and-deploy-testnet`:
      Executed after merges to `main` or when dispatched manually.
      Uses unmodified contracts (tagged `goerli`).
      Publishes testnet dApp to `dashboard.test.threshold.network`
      bucket.
- `build-and-deploy-testnet-preview`:
      Executed after PR creation/update.
      Uses modified contracts when availible
      (tagged `dappdevgoerli`).
      Publishes testnet dApp to
      `preview.dashboard.test.threshold.network` bucket.
      Provides link to the preview in PR comment.

.github/workflows/dashboard-ci.yaml

@@ -55,6 +55,8 @@ jobs:
       - name: Configure git to don't use unauthenticated protocol
         run: git config --global url."https://".insteadOf git://
 
+      # TODO: Add upgrade of @keep-network/random-beacon, @keep-network/ecdsa,
+      # @keep-network/tbtc-v2 once they'll be added as dashboard's dependencies.
       - name: Resolve latest contracts
         run: |
           yarn upgrade \
@@ -80,9 +82,10 @@ jobs:
       # - name: Test
       #   run: yarn test
 
-  build-and-deploy-testnet:
+  build-and-deploy-testnet-preview:
     name: Deploy to testnet
     needs: build-and-test
+    if: github.event_name == 'pull_request'
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
@@ -103,10 +106,12 @@ jobs:
       # We provide explicit version of the `keep-core` package, because using
       # `goerli` tag results in `expected manifest` error - probably caused by
       # bug in Yarn: https://github.com/yarnpkg/yarn/issues/4731.
+      # TODO: Add upgrade of @keep-network/random-beacon, @keep-network/ecdsa,
+      # @keep-network/tbtc-v2 once they'll be added as dashboard's dependencies.
       - name: Resolve latest goerli contracts
         run: |
           yarn upgrade \
-            @threshold-network/solidity-contracts@goerli \
+            @threshold-network/solidity-contracts@dapp-development-goerli \
             @keep-network/[email protected] \
             @keep-network/keep-ecdsa@goerli \
             @keep-network/tbtc@goerli \
@@ -124,9 +129,7 @@ jobs:
           ETH_HOSTNAME_HTTP: ${{ secrets.GOERLI_ETH_HOSTNAME_HTTP }}
           ETH_HOSTNAME_WS: ${{ secrets.GOERLI_ETH_HOSTNAME_WS }}
 
-      # A pull_request event is a PR; deploy to preview testnet bucket.
       - name: Deploy PR preview to GCP
-        if: github.event_name == 'pull_request'
         uses: thesis/[email protected]
         with:
           service-key: ${{ secrets.KEEP_TEST_CI_UPLOAD_DAPP_JSON_KEY_BASE64 }}
@@ -136,7 +139,6 @@ jobs:
           build-folder: build
 
       - name: Post preview URL to PR
-        if: github.event_name == 'pull_request'
         uses: actions/github-script@v5
         with:
           script: |
@@ -147,13 +149,57 @@ jobs:
               body: 'Preview uploaded to https://preview.dashboard.test.threshold.network/${{ github.head_ref }}/index.html.'
             })
 
-      # A push event is triggered on main branch merge; deploy to testnet
-      # bucket. Also triggered by manual dispatch from `main` branch.
+  build-and-deploy-testnet:
+    name: Deploy to testnet
+    needs: build-and-test
+    if: |
+      github.event_name == 'push'
+        || (github.event_name == 'workflow_dispatch'
+        && github.ref == 'refs/heads/main')
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+
+      - uses: actions/setup-node@v2
+        with:
+          node-version: "16"
+          cache: "yarn"
+
+      # We need this step because the `@keep-network/tbtc` which we update in
+      # next step has a dependency to `@summa-tx/[email protected]` package, which
+      # downloads one of its sub-dependencies via unathenticated `git://`
+      # protocol. That protocol is no longer supported. Thanks to this step
+      # `https://` is used instead of `git://`.
+      - name: Configure git to don't use unauthenticated protocol
+        run: git config --global url."https://".insteadOf git://
+
+      # We provide explicit version of the `keep-core` package, because using
+      # `goerli` tag results in `expected manifest` error - probably caused by
+      # bug in Yarn: https://github.com/yarnpkg/yarn/issues/4731.
+      # TODO: Add upgrade of @keep-network/random-beacon, @keep-network/ecdsa,
+      # @keep-network/tbtc-v2 once they'll be added as dashboard's dependencies.
+      - name: Resolve latest goerli contracts
+        run: |
+          yarn upgrade \
+            @threshold-network/solidity-contracts@goerli \
+            @keep-network/[email protected] \
+            @keep-network/keep-ecdsa@goerli \
+            @keep-network/tbtc@goerli \
+            @keep-network/coverage-pools@goerli
+
+      - name: Run postinstall script
+        # `yarn upgrade` doesn't trigger the `postinstall` script.
+        run: yarn run postinstall
+
+      - name: Build
+        run: yarn build
+        env:
+          PUBLIC_URL: /${{ github.head_ref }}
+          CHAIN_ID: 5
+          ETH_HOSTNAME_HTTP: ${{ secrets.GOERLI_ETH_HOSTNAME_HTTP }}
+          ETH_HOSTNAME_WS: ${{ secrets.GOERLI_ETH_HOSTNAME_WS }}
+
       - name: Deploy to GCP bucket
-        if: |
-          github.event_name == 'push'
-          || (github.event_name == 'workflow_dispatch'
-          && github.ref == 'refs/heads/main')
         uses: thesis/[email protected]
         with:
           service-key: ${{ secrets.KEEP_TEST_CI_UPLOAD_DAPP_JSON_KEY_BASE64 }}