ci(e2e): run Cypress only when frontend paths change

.github/workflows/ci.yml

@@ -15,6 +15,25 @@ permissions:
   contents: read
 
 jobs:
+  changes:
+    runs-on: ubuntu-latest
+    outputs:
+      e2e: ${{ steps.filter.outputs.e2e }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Detect changes for E2E
+        id: filter
+        uses: dorny/paths-filter@v3
+        with:
+          filters: |
+            e2e:
+              - 'frontend/**'
+              - 'frontend/cypress/**'
+              - 'frontend/package.json'
+              - 'frontend/package-lock.json'
+              - '.github/workflows/ci.yml'
+
   check:
     runs-on: ubuntu-latest
 
@@ -99,7 +118,8 @@ jobs:
 
   e2e:
     runs-on: ubuntu-latest
-    needs: [check]
+    needs: [check, changes]
+    if: needs.changes.outputs.e2e == 'true'
 
     steps:
       - name: Checkout