Drop Python 3.8 from test matrix

b/c black 24.10.0 Requires-Python >=3.9

Author: atodorov

.github/workflows/lint.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.8, 3.11]
+        python-version: [3.11]
 
     steps:
       - uses: actions/checkout@v3

.github/workflows/testing.yml

@@ -15,7 +15,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: [3.8, 3.11]
+        python-version: [3.11]
         make-command: [doc8, flake8, pylint, check-build]
 
     steps:
@@ -42,7 +42,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: [3.8, 3.11]
+        python-version: [3.11]
         kiwitcms-url: [public.tenant.kiwitcms.org, tcms.kiwitcms.org]
 
     steps: