Fetch entire history

Author: lang-m

.github/workflows/check-changelog.yml

@@ -7,6 +7,8 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
       - uses: actions/setup-python@v5
         with:
           python-version: '3.13'