Update MySQL test matrix

MySQL 8.1 has been EOL since 2023-10-25. Use the next LTS 8.4
(2032-04-30). Add MYSQL_ROOT_PASSWORD to ensure the root password
is set.

Also use email user model and disable timezone on the 8.4 strategy to
ensure we test these configurations with MySQL as well.

.github/workflows/test.yml

@@ -23,7 +23,7 @@ concurrency:
 # - django 4.2, python 3.9, postgres:12, psycopg 2, parallel
 # - django 4.2, python 3.10, mysql:8.0
 # - django 5.0, python 3.11, sqlite, WAGTAIL_CHECK_TEMPLATE_NUMBER_FORMAT=1
-# - django 5.1, python 3.12, mysql:8.1, parallel
+# - django 5.1, python 3.12, mysql:8.4, parallel, USE_EMAIL_USER_MODEL=yes, DISABLE_TIMEZONE=yes
 # - django 5.1, python 3.12, sqlite, parallel, USE_EMAIL_USER_MODEL=yes
 # - django 5.1, python 3.12, postgres:15, psycopg 3, parallel, DISABLE_TIMEZONE=yes
 # - django stable/5.1.x, python 3.11, postgres:15, psycopg 3 (allow failures)
@@ -165,11 +165,14 @@ jobs:
             django: 'Django>=5.1,<5.2'
             experimental: false
             parallel: '--parallel'
-            mysql: 'mysql:8.1'
+            mysql: 'mysql:8.4'
+            emailuser: emailuser
+            notz: notz
     services:
       mysql:
         image: ${{ matrix.mysql || 'mysql:8.0' }}
         env:
+          MYSQL_ROOT_PASSWORD: root
           MYSQL_ALLOW_EMPTY_PASSWORD: yes
           MYSQL_DATABASE: wagtail
         ports:
@@ -197,6 +200,9 @@ jobs:
           DATABASE_ENGINE: django.db.backends.mysql
           DATABASE_HOST: '127.0.0.1'
           DATABASE_USER: root
+          DATABASE_PASSWORD: root
+          USE_EMAIL_USER_MODEL: ${{ matrix.emailuser }}
+          DISABLE_TIMEZONE: ${{ matrix.notz }}
       - name: Upload coverage data
         uses: actions/upload-artifact@v4
         with: