Test against supported versions of postgres and mariadb (#835)

Author: albertyw

.github/workflows/test.yml

@@ -11,15 +11,9 @@ jobs:
       matrix:
         python-version: ['3.10', '3.11', '3.12', '3.13', '3.14']
         django-version: ['4.2', '5.1', '5.2', 'main']
-        postgres-version: ['13', '17']
-        mariadb-version: ['10.6', '10.11', '11.4']
+        postgres-version: ['14', '18']
+        mariadb-version: ['10.6', '10.11', '11.4', '11.8']
         exclude:
-          # Django 5.2 doesn't support Postgres 13 (https://docs.djangoproject.com/en/5.2/releases/5.2/#dropped-support-for-postgresql-13)
-          - django-version: '5.2'
-            postgres-version: '13'
-          - django-version: 'main'
-            postgres-version: '13'
-
           # Django 4.2 doesn't support Python >= 3.13
           - django-version: '4.2'
             python-version: '3.13'