Don't have to run mypy on 3.8 in order to enforce 3.8 annotations

Author: erlend-aasland

.github/workflows/pythonpackage.yml

@@ -61,7 +61,7 @@ jobs:
     - uses: actions/checkout@v4
     - uses: actions/setup-python@v5
       with:
-        python-version: "3.8"
+        python-version: 3.12
         cache: pip
         cache-dependency-path: |
           'pyproject.toml'