[CI] use native concurrency to cancel previous CI runs

.github/workflows/ci.yml

@@ -18,16 +18,13 @@ on:
 env:
   VERBOSE: ${{ github.events.input.verbose }}
 
+# Cancel a currently running workflow from the same PR, branch or tag when a new workflow is
+# triggered (ref https://stackoverflow.com/a/72408109)
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
 
 jobs:
-  cancel_previous_runs:
-    name: Cancel Previous Runs
-    runs-on: ubuntu-20.04
-    steps:
-      - uses: styfle/[email protected]
-        with:
-          access_token: ${{ secrets.GITHUB_TOKEN }}
-
   build_primary_binaries:
     name: Primary build ${{ matrix.binary }} for ${{ matrix.rust-target }} on (${{ matrix.os }})
     runs-on: ${{ matrix.os }}