Add concurrency to testing CI workflow

Introduce a concurrency block to the testing CI workflow so runs for the same PR are grouped and previous in-progress jobs are cancelled when a new update is pushed. The group is keyed by workflow and pull request number (ci-${{ github.workflow }}-pr-${{ github.event.pull_request.number }}) to avoid redundant CI runs and save resources.

Author: C-Achard

.github/workflows/testing-ci.yml

@@ -4,6 +4,10 @@ on:
   pull_request:
     types: [opened, synchronize, reopened]
 
+concurrency:
+  group: ci-${{ github.workflow }}-pr-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
 jobs:
   unit:
     name: Unit + Smoke (no hardware) • ${{ matrix.os }} • py${{ matrix.python }}