fix: use the branch's name in the concurrency group (#50)

Author: xorsal

.github/workflows/tests.yml

@@ -3,7 +3,7 @@ name: Tests
 on: [push]
 
 concurrency:
-  group: pr-${{ github.head_ref }}
+  group: ${{ github.workflow }}-${{ github.ref_name }}
   cancel-in-progress: true
 
 jobs: