Fix Codecov badge by adding OIDC permission for tokenless upload

The codecov-action v5 requires `id-token: write` to authenticate via OIDC when no CODECOV_TOKEN is provided. Without it the upload silently fails (fail_ci_if_error: false) leaving the badge as "unknown".

The Codecov GitHub App is already installed on the WordPress org, so OIDC-based tokenless uploads work once this permission is granted.

Author: nimesh-xecurify

.github/workflows/test.yml

@@ -65,6 +65,8 @@ jobs:
     test-php:
         name: Test PHP ${{ matrix.php }} ${{ matrix.wp != '' && format( ' (WP {0}) ', matrix.wp ) || '' }}
         runs-on: ubuntu-24.04
+        permissions:
+            id-token: write
         strategy:
             matrix:
                 php: