Update peter-evans/create-pull-request action to v6

Author: renovate[bot]

.github/workflows/plan-release.yml

@@ -71,7 +71,7 @@ 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] <github-actions-bot@users.noreply.github.com>"