versioncheck: Use newer upload/artifact version to match download-art…

…ifact version.

Version 2 is deprecated.  Or rather it completely fails:
https://github.com/plone/buildout.coredev/actions/runs/10829157719/job/30046098338

Let's also use a more recent Python.  This is the same as on Plone 6.1.

.github/workflows/versioncheck.yml

@@ -9,7 +9,7 @@ jobs:
     strategy:
       matrix:
         python-version:
-        - "3.8"
+        - "3.10"
     runs-on: ubuntu-latest
 
     steps:
@@ -41,7 +41,7 @@ jobs:
       run: |
          ./bin/versioncheck -pnNbo versions.html
     - name: Upload versions.html
-      uses: actions/upload-artifact@v2
+      uses: actions/upload-artifact@v4
       with:
         name: versions-${{ matrix.python-version }}
         path: versions.html