Bump actions/upload-artifact from 5 to 6 (#611)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/pypi.yaml

@@ -41,7 +41,7 @@ jobs:
           else
             echo "✅ Looks good"
           fi
-      - uses: actions/upload-artifact@v5
+      - uses: actions/upload-artifact@v6
         with:
           name: releases
           path: dist

.github/workflows/testpypi-release.yaml

@@ -53,7 +53,7 @@ jobs:
             echo "✅ Looks good"
           fi
 
-      - uses: actions/upload-artifact@v5
+      - uses: actions/upload-artifact@v6
         with:
           name: releases
           path: dist