Chore: Allow concurrency on default branch (#639)

Author: BeyondEvil

.github/workflows/tests.yml

@@ -12,7 +12,7 @@ on:
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
-  cancel-in-progress: true
+  cancel-in-progress: ${{ github.ref != github.event.repository.default_branch }}
 
 jobs:
   build_docs: