CI: preserve credentials from checkout

We need them later.

Author: tacaswell

.github/workflows/update-changelog.yaml

@@ -19,7 +19,7 @@ jobs:
         uses: actions/checkout@v2
         with:
           ref: main
-          persist-credentials: false
+          persist-credentials: true
 
       - name: Update Changelog
         uses: stefanzweifel/changelog-updater-action@a938690fad7edf25368f37e43a1ed1b34303eb36 # v1