ci: suppress Node.js 20 deprecation warning and gate integration tests on unit tests

- Add FORCE_JAVASCRIPT_ACTIONS_TO_NODE24=true workflow env to opt into
  Node.js 24 early and suppress the actions/checkout@v4 deprecation warning
- Add 'needs: unit-tests' to integration-tests job so it is skipped
  automatically when unit tests fail

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: Pierre-Luc Gagné

.github/workflows/ci.yml

@@ -7,6 +7,9 @@ on:
     branches: [main]
   workflow_dispatch:
 
+env:
+  FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: 'true'
+
 jobs:
   unit-tests:
     runs-on: ubuntu-latest
@@ -42,6 +45,7 @@ jobs:
         run: ctest --preset release
 
   integration-tests:
+    needs: unit-tests
     runs-on: ubuntu-latest
 
     env: