Fetch pinned workflow helpers in contract CI

Author: chubes4

.github/workflows/agent-task-contracts.yml

@@ -35,6 +35,8 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
       - uses: actions/setup-node@v4
         with:
           node-version: 22