Update automerge workflow to merge release/6.3 into main

Author: jakepetroules

.github/workflows/automerge.yml

@@ -9,10 +9,10 @@ on:
   workflow_dispatch:
 jobs:
   create_merge_pr:
-    name: Create PR to merge main into release branch
+    name: Create PR to merge release into main branch
     uses: swiftlang/github-workflows/.github/workflows/create_automerge_pr.yml@main
     with:
-      head_branch: release/6.2
+      head_branch: release/6.3
       base_branch: main
     permissions:
       contents: write