ci: concurrency control for CI jobs (#27230)

similar to https://github.com/frappe/frappe/pull/14061

This will ensure that only one instance of the following tests run per
PR and cancel previous running/queued jobs when new commits are pushed.

- Server / unit tests
- UI tests
- Patch test

.github/workflows/patch.yml

@@ -7,6 +7,9 @@ on:
       - '**.md'
   workflow_dispatch:
 
+concurrency:
+  group: patch-develop-${{ github.event.number }}
+  cancel-in-progress: true
 
 jobs:
   test: