Automatically add all packs to packs workflow

.github/workflows/packs.yaml

@@ -4,13 +4,24 @@ on:
   push:
     branches:
       - main
+  pull_request:
+    branches:
+      - main
 
 jobs:
+  list-packs:
+    runs-on: ubuntu-latest
+    outputs:
+      matrix: ${{ steps.set-matrix.outputs.matrix }}
+    steps:
+      - uses: actions/checkout@v4
+      - id: set-matrix
+        run: echo "::set-output name=matrix::$(ls packs/*.csv | jq -R -s -c 'split("\n")[:-1]')"
   run_emulations:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        pack: ["packs/cats.csv","packs/elements.csv","packs/famous-art-robberies.csv","packs/harry-potter-and-the-deathly-hallows-part-2.csv","packs/mcdonalds-baby-animals.csv","packs/mcdonalds-minions-rise-of-gru.csv","packs/star-wars-rise-of-the-bounty-hunters.csv","packs/star-wars-starships.csv","packs/the-art-game.csv","packs/the-big-bang-theory.csv"]  # ls -1 packs/*.csv | jq -Rsc 'split("\n")[:-1]'
+        pack: ${{ fromJson(needs.list-packs.outputs.matrix) }}
     steps:
       - name: Checkout
         uses: actions/checkout@v4