Migrate to upload/download-artifact@v4

Artifacts were made immutable: https://github.com/actions/upload-artifact/blob/main/docs/MIGRATION.md\#multiple-uploads-to-the-same-named-artifact

.github/workflows/publish.yml

@@ -123,7 +123,7 @@ jobs:
 
       - uses: actions/upload-artifact@v4
         with:
-          name: dist
+          name: dist_${{ matrix.os }}
           path: |
             ./wheelhouse/*.whl
             !./wheelhouse/UNKNOWN*.whl
@@ -154,7 +154,7 @@ jobs:
 
       - uses: actions/upload-artifact@v4
         with:
-          name: dist
+          name: dist_windows
           path: |
             ./wheelhouse/*.whl
             !./wheelhouse/UNKNOWN*.whl
@@ -193,7 +193,7 @@ jobs:
 
       - uses: actions/upload-artifact@v4
         with:
-          name: dist
+          name: dist_source
           path: dist/*.tar.gz
 
   publish_to_test_pypi:
@@ -220,7 +220,8 @@ jobs:
       - uses: actions/download-artifact@v4
         id: download
         with:
-          name: dist
+          pattern: dist_*
+          merge-multiple: true
           path: dist/
 
       - name: Publish package to TestPyPI