build: remove e2e "proxy" (#1904)

# Motivation

`npm ci` in CI for `e2e-tests` is failing because it complains about missing dependencies which are inherited by `proxy` even though these are effectively installed there.

As we are not using the `proxy` anymore, this PR removes it and per extension solve the CI current issue.

# Changes

- `rm -r ./proxy && cd e2e-test && npm rm proxy`

.dockerignore

@@ -18,7 +18,6 @@ web-assets
 frontend/node_modules/
 frontend/public/build/
 frontend/public/assets/
-proxy
 e2e-tests
 **/*.wasm
 /deployment-config.json

.gitignore

@@ -97,8 +97,6 @@ out
 !**/ios/**/default.pbxuser
 !**/ios/**/default.perspectivev3
 
-proxy/build/
-proxy/node_modules
 canister_ids.json
 canister_ids.json.*
 e2e-tests/node_modules