ci: replace deprecated actions/create-release by ncipollo/release-action

https://github.com/actions/create-release is deprecated so we should
stop using it. ncipollo/release-action is one of its maintained
replacements, and the one our mathieudutour/github-tag-action actions
uses in their documentation.

Linted with https://rhysd.github.io/actionlint/ but we can't really test
this without creating a new release, so we'll have to test it when it's
time to create the next release.

Fixes #200

.github/workflows/pythonpublish.yml

@@ -47,10 +47,8 @@ jobs:
         github_token: ${{ secrets.GITHUB_TOKEN }}
         custom_tag: ${{ steps.determine_tag.outputs.TAG_VERSION }}
     - name: Create a GitHub release
-      uses: actions/create-release@v1
-      env:
-        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      uses: ncipollo/release-action@v1
       with:
-        tag_name: ${{ steps.tag_version.outputs.new_tag }}
-        release_name: Release ${{ steps.tag_version.outputs.new_tag }}
+        tag: ${{ steps.tag_version.outputs.new_tag }}
+        name: Release ${{ steps.tag_version.outputs.new_tag }}
         body: ${{ steps.tag_version.outputs.changelog }}