[prtester] Optimize tester workflow (#4303)

.github/workflows/prhtmlgenerator.yml

@@ -5,9 +5,24 @@ on:
     branches: [ master ]
 
 jobs:
+  check-bridges:
+    name: Check if bridges were changed
+    runs-on: ubuntu-latest
+    outputs:
+      BRIDGES: ${{ steps.check1.outputs.BRIDGES }}
+    steps:
+      - name: Check number of bridges
+        id: check1
+        run: |
+          PR=${{github.event.number}};
+          wget https://patch-diff.githubusercontent.com/raw/$GITHUB_REPOSITORY/pull/$PR.patch;
+          bridgeamount=$(cat $PR.patch | grep "\bbridges/[A-Za-z0-9]*Bridge\.php\b" | sed "s=.*\bbridges/\([A-Za-z0-9]*\)Bridge\.php\b.*=\1=g" | sort | uniq | wc -l);
+          echo "BRIDGES=$bridgeamount" >> "$GITHUB_OUTPUT"
   test-pr:
     name: Generate HTML
     runs-on: ubuntu-latest
+    needs: check-bridges
+    if: needs.check-bridges.outputs.BRIDGES > 0
     env:
       PYTHONUNBUFFERED: 1
     # Needs additional permissions https://github.com/actions/first-interaction/issues/10#issuecomment-1041402989