Bump CI artifact to v4.

Author: eerimoq

.github/workflows/release.yml

@@ -30,7 +30,7 @@ jobs:
       - name: Build wheels
         run: python -m cibuildwheel --output-dir wheelhouse
 
-      - uses: actions/upload-artifact@v3
+      - uses: actions/upload-artifact@v4
         with:
           path: ./wheelhouse/*.whl
 
@@ -47,7 +47,7 @@ jobs:
       - name: Build sdist
         run: pipx run build --sdist
 
-      - uses: actions/upload-artifact@v3
+      - uses: actions/upload-artifact@v4
         with:
           path: dist/*.tar.gz
 
@@ -56,7 +56,7 @@ jobs:
     needs: [build_wheels, build_sdist]
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/download-artifact@v3
+      - uses: actions/download-artifact@v4
         with:
           name: artifact
           path: dist