Only run workflows if they might be able to work (#63164)

.github/workflows/issue-labeled.yml

@@ -5,7 +5,22 @@ on:
     types: [labeled]
 
 jobs:
+  config:
+    runs-on: "ubuntu-latest"
+    outputs:
+      has-secrets: ${{ steps.check.outputs.has-secrets }}
+    steps:
+      - name: "Check for secrets"
+        id: check
+        shell: bash
+        run: |
+          if [ -n "${{ (secrets.SLACK_WEBHOOK_URL != '') || '' }}" ]; then
+            echo "has-secrets=1" >> "$GITHUB_OUTPUT"
+          fi
+
   notify:
+    needs: config
+    if: needs.config.outputs.has-secrets
     runs-on: ubuntu-latest
     steps:
       - name: "Download teams.yml to know which label is for which team"