chore(build): guard gitleaks license and pin action SHA

Author: sklarsa

.github/workflows/gitleaks.yml

@@ -13,7 +13,8 @@ jobs:
       - uses: actions/checkout@v4
         with:
           fetch-depth: 0
-      - uses: gitleaks/gitleaks-action@v2
+      - uses: gitleaks/gitleaks-action@83d9cd684c87d95d656c1458ef04895a7f1cbd8e
+        if: ${{ secrets.GITLEAKS_LICENSE != '' }}
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           GITLEAKS_LICENSE: ${{ secrets.GITLEAKS_LICENSE }}