Drop support for Python 3.8 and refresh poetry.lock.

Author: felixxm

.github/workflows/ci.yml

@@ -19,26 +19,20 @@ jobs:
       fail-fast: true
       max-parallel: 4
       matrix:
-        python-version: [3.8, 3.9, '3.10', '3.11', '3.12', '3.13']
+        python-version: [3.9, '3.10', '3.11', '3.12', '3.13']
         django-version: [4.2, '5.0', 5.1, 5.2]
         exclude:
           # Django 4.2 only supports Python 3.8 to 3.12.
           - python-version: 3.13
             django-version: 4.2
           # Django 5.0 only supports Python 3.10 to 3.12.
-          - python-version: 3.8
-            django-version: 5.0
           - python-version: 3.9
             django-version: 5.0
           - python-version: 3.13
             django-version: 5.0
           # Django 5.1 and 5.2 only support Python 3.10 to 3.13.
-          - python-version: 3.8
-            django-version: 5.1
           - python-version: 3.9
             django-version: 5.1
-          - python-version: 3.8
-            django-version: 5.2
           - python-version: 3.9
             django-version: 5.2