Update peter-evans/create-pull-request action to v6 (#547)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/plan-release.yml

@@ -61,7 +61,7 @@ jobs:
         env:
           GITHUB_AUTH: ${{ secrets.GITHUB_TOKEN }}
 
-      - uses: peter-evans/create-pull-request@v5
+      - uses: peter-evans/create-pull-request@v6
         with:
           commit-message: "Prepare Release using 'release-plan'"
           author: "github-actions[bot] <[email protected]>"