cancel running ci workflows for pr branches (#264)

.github/workflows/continuous-integration.yaml

@@ -17,6 +17,11 @@ on:
 
   workflow_dispatch:
 
+# cancel same workflows in progress for pull request branches
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.ref != 'refs/heads/main' }}
+
 
 # global env vars, available in all jobs and steps
 env:
@@ -35,6 +40,9 @@ jobs:
     name: Unit tests
     runs-on: ubuntu-latest
 
+    # max run time 5 minutes
+    timeout-minutes: 5
+
     steps:
       - uses: actions/checkout@v3
 
@@ -55,6 +63,9 @@ jobs:
     needs: [ build ]
     runs-on: ubuntu-latest
 
+    # max run time 20 minutes
+    timeout-minutes: 20
+
     strategy:
 
       # let all tests run, can find multiple failures in different setup