Fix GitHub Actions workflow failures

- Add WP_PHPUNIT__DIR and WP_TESTS_DIR environment variables to PHPUnit workflow to fix 'WP_UnitTestCase not found' error
- Increase WordPress Playground server timeout from 60s to 180s with better progress logging to fix timeout failures
- Add conditional checks for SONAR_TOKEN and CODACY_PROJECT_TOKEN to gracefully skip analysis when tokens are not set
- Properly handle server process lifecycle in Playground tests (capture PID, kill on completion)

.github/workflows/phpunit.yml

@@ -57,6 +57,9 @@ jobs:
           echo "WordPress test suite installed successfully"
 
       - name: Run PHPUnit tests
+        env:
+          WP_PHPUNIT__DIR: /tmp/wordpress-tests-lib
+          WP_TESTS_DIR: /tmp/wordpress-tests-lib
         run: |
           if [ "${{ matrix.multisite }}" = "true" ]; then
             WP_MULTISITE=1 composer test