Update GitLab Download Artifact action to v4

Author: acdha

.github/workflows/pypi-release.yml

@@ -28,7 +28,7 @@ jobs:
         permissions:
             id-token: write
         steps:
-            - uses: actions/download-artifact@v3
+            - uses: actions/download-artifact@v4
               with:
                   # unpacks default artifact into dist/
                   # if `name: artifact` is omitted, the action will create extra parent dir