Fix deprecated metadata key

- fixes #137

Author: mrbean-bremen

.github/workflows/pythontests.yml

@@ -35,7 +35,6 @@ jobs:
       run: |
         python -m pip install -U pip # to ensure version > 20 to have cache dir
         echo "dir=$(pip cache dir)" >> $GITHUB_OUTPUT
-        echo "dir=$(pip cache dir)" >> $env:GITHUB_OUTPUT
     - name: pip cache
       uses: actions/cache@v4
       with:

setup.cfg

@@ -1,5 +1,5 @@
 [metadata]
-description-file = README.md
+description_file = README.md
 license_files = LICENSE
 [bdist_wheel]
 universal=0