Add inter-branch merge workflow configuration (#2692)

Co-authored-by: Viktor Hofer <[email protected]>

Author: github-actions[bot]

.github/workflows/inter-branch-merge-flow.yml

@@ -0,0 +1,13 @@
+name: Inter-branch merge workflow
+on:
+  push:
+    branches:
+      - release/**
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  Merge:
+    uses: dotnet/arcade/.github/workflows/inter-branch-merge-base.yml@main