fix(ci): Guard Codecov upload when token is unavailable

Author: seebeen

.github/workflows/tests.yml

@@ -19,6 +19,8 @@ jobs:
     name: PHPUnit (PHP ${{ matrix.php }})
     runs-on: ubuntu-latest
     continue-on-error: ${{ matrix.php == '8.5' }}
+    env:
+      CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
     strategy:
       fail-fast: false
       matrix:
@@ -54,16 +56,16 @@ jobs:
         run: composer test:unit
 
       - name: Upload coverage to Codecov
-        if: ${{ matrix.php == '8.1' && secrets.CODECOV_TOKEN != '' }}
+        if: ${{ matrix.php == '8.1' && env.CODECOV_TOKEN != '' }}
         uses: codecov/codecov-action@v5
         with:
           files: build/coverage.xml
           disable_search: true
           fail_ci_if_error: true
-          token: ${{ secrets.CODECOV_TOKEN }}
+          token: ${{ env.CODECOV_TOKEN }}
 
       - name: Skip Codecov upload (missing CODECOV_TOKEN)
-        if: ${{ matrix.php == '8.1' && secrets.CODECOV_TOKEN == '' }}
+        if: ${{ matrix.php == '8.1' && env.CODECOV_TOKEN == '' }}
         run: echo "Codecov upload skipped because CODECOV_TOKEN is not configured for this workflow context."
 
   integration-live: