auto-cancel wheels CI if new run triggered on non-default branch

Author: 2bndy5

.github/workflows/wheels.yml

@@ -1,5 +1,9 @@
 name: Wheels
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.ref_name != 'master' }}
+
 on:
   push:
     branches: [master]