Remove support for various Django and Python version

Add support for Python 3.12.0 and latest patch versions of Django
Simplify compatibility table on README
Bump version to v3.12.0 (coincidentally aligning with Python releases)

Author: mostafa

.flake8

@@ -2,6 +2,7 @@
     max-line-length = 100
     per-file-ignores =
         django_saml2_auth/tests/test_saml.py: E501, F821
+        django_saml2_auth/saml.py: E231
     exclude =
         django_saml2_auth.egg-info,
         dist,

.github/workflows/deploy.yml

@@ -15,17 +15,12 @@ jobs:
     strategy:
       matrix:
         versions:
-          - { "djangoVersion": "3.2.20", "pythonVersion": "3.7" }
-          - { "djangoVersion": "3.2.20", "pythonVersion": "3.8" }
-          - { "djangoVersion": "3.2.20", "pythonVersion": "3.9" }
-          - { "djangoVersion": "3.2.20", "pythonVersion": "3.10" }
-          - { "djangoVersion": "4.1.10", "pythonVersion": "3.8" }
-          - { "djangoVersion": "4.1.10", "pythonVersion": "3.9" }
-          - { "djangoVersion": "4.1.10", "pythonVersion": "3.10" }
-          - { "djangoVersion": "4.2.3", "pythonVersion": "3.8" }
-          - { "djangoVersion": "4.2.3", "pythonVersion": "3.9" }
-          - { "djangoVersion": "4.2.3", "pythonVersion": "3.10" }
-          - { "djangoVersion": "4.2.3", "pythonVersion": "3.11" }
+          - { "djangoVersion": "3.2.23", "pythonVersion": "3.9" }
+          - { "djangoVersion": "3.2.23", "pythonVersion": "3.10" }
+          - { "djangoVersion": "4.2.7", "pythonVersion": "3.9" }
+          - { "djangoVersion": "4.2.7", "pythonVersion": "3.10" }
+          - { "djangoVersion": "4.2.7", "pythonVersion": "3.11" }
+          - { "djangoVersion": "4.2.7", "pythonVersion": "3.12" }
     steps:
       - name: Checkout 🛎️
         uses: actions/checkout@v3