don't cancel the tests on main automatically for concurrency (#2055) [skip ci]

.github/workflows/tests.yml

@@ -18,7 +18,7 @@ on:
 # Cancel jobs on the same ref if a new one is triggered
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
-  cancel-in-progress: true
+  cancel-in-progress: ${{ github.ref != 'refs/heads/main' }}
 
 jobs:
   pre-commit: