CI: add PHP 8.4 coverage

Add Drupal 11 + PHP 8.4 required, and Drupal 11 + PHP 8.5 allow-failure.

Author: mowens3

.github/workflows/drupal-module.yml

@@ -19,14 +19,23 @@ on:
 jobs:
   phpunit:
     runs-on: ubuntu-latest
+    continue-on-error: ${{ matrix.experimental }}
     strategy:
       fail-fast: false
       matrix:
         include:
           - drupal: "^10"
             php: "8.2"
+            experimental: false
           - drupal: "^11"
             php: "8.3"
+            experimental: false
+          - drupal: "^11"
+            php: "8.4"
+            experimental: false
+          - drupal: "^11"
+            php: "8.5"
+            experimental: true
 
     env:
       SIMPLETEST_BASE_URL: "http://127.0.0.1"