ci: add path filtering to performance testing workflow

.github/workflows/performance.yml

@@ -12,10 +12,38 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
+  changes:
+    runs-on: ubuntu-latest-low
+    permissions:
+      contents: read
+      pull-requests: read
+
+    outputs:
+      src: ${{ steps.changes.outputs.src }}
+
+    steps:
+      - uses: dorny/paths-filter@de90cc6fb38fc0963ad72b210f1f284cd68cea36 # v3.0.2
+        id: changes
+        continue-on-error: true
+        with:
+          filters: |
+            src:
+              - '.github/workflows/**'
+              - '3rdparty/**'
+              - '**/appinfo/**'
+              - '**/lib/**'
+              - '**/templates/**'
+              - 'vendor/**'
+              - 'vendor-bin/**'
+              - 'composer.json'
+              - 'composer.lock'
+              - '**.php'
+
   performance-testing:
     runs-on: ubuntu-latest
 
-    if: ${{ github.repository_owner != 'nextcloud-gmbh' }}
+    needs: changes
+    if: ${{ needs.changes.outputs.src != 'false' && github.repository_owner != 'nextcloud-gmbh' }}
 
     permissions:
       pull-requests: write