Fix versioning workflow checkout for push events (#469)

Remove PR-specific context variables (github.event.pull_request.head.repo.full_name
and github.event.pull_request.head.ref) from the checkout step. These are undefined
for push events, causing checkout to fail.

Fixes #468

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude <noreply@anthropic.com>

Author: baogorek

.github/workflows/versioning.yaml

@@ -18,8 +18,6 @@ jobs:
           - name: Checkout repo
             uses: actions/checkout@v4
             with:
-              repository: ${{ github.event.pull_request.head.repo.full_name }}
-              ref: ${{ github.event.pull_request.head.ref }}
               token: ${{ secrets.POLICYENGINE_GITHUB }}
           - name: Setup Python
             uses: actions/setup-python@v5

changelog_entry.yaml

@@ -1,7 +1,4 @@
-- bump: minor
+- bump: patch
   changes:
-    added:
-    - Modal integration for CI/CD workflows, replacing self-hosted GCP runners
-    changed:
-    - Updated reusable_test.yaml to trigger data builds on Modal
-    - Updated local_area_publish.yaml to run on Modal
+    fixed:
+    - Versioning workflow checkout for push events