Merge pull request #489 from daq-tools/ci-concurrency

CI: Cancel redundant in-progress workflow runs

Author: martindurant

.github/workflows/main.yaml

@@ -5,6 +5,12 @@ on:
     branches: "*"
   pull_request:
     branches: master
+  workflow_dispatch:
+
+# Cancel redundant in-progress workflow runs.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
 
 jobs:
   test: