Change destination_branch to dev/5.1.x

.github/workflows/release.yml

@@ -114,7 +114,7 @@ jobs:
       uses: repo-sync/pull-request@v2
       with:
         source_branch: support/prepare-v${{ steps.package-json.outputs.packageVersion }}
-        destination_branch: master
+        destination_branch: dev/5.1.x
         pr_title: Prepare v${{ steps.package-json.outputs.packageVersion }}
         pr_label: exclude from changelog
         pr_body: "An automated PR generated by ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY}/actions/runs/${GITHUB_RUN_ID}"