Cancel ongoing actions on push.

https://docs.github.com/en/actions/using-jobs/using-concurrency

Author: nihohit

.github/workflows/rust.yml

@@ -10,6 +10,10 @@ env:
   CARGO_TERM_COLOR: always
   REDIS_RS_REDIS_JSON_PATH: "/tmp/librejson.so"
 
+concurrency:
+  group: group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
 jobs:
   build: