Bump actions/{up,down}load-artifact from 3 to 4 (#833)

Bumps
[actions/download-artifact](https://github.com/actions/download-artifact)
from 3 to 4.
- [Release notes](https://github.com/actions/download-artifact/releases)
-
[Commits](actions/download-artifact@v3...v4)

Bumps
[actions/upload-artifact](https://github.com/actions/upload-artifact)
from 3 to 4.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v3...v4)

Author: llucax

.github/workflows/ci.yaml

@@ -230,7 +230,7 @@ jobs:
         run: python -m build
 
       - name: Upload distribution files
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: dist-packages
           path: dist/
@@ -244,7 +244,7 @@ jobs:
       - name: Fetch sources
         uses: actions/checkout@v4
       - name: Download package
-        uses: actions/download-artifact@v3
+        uses: actions/download-artifact@v4
         with:
           name: dist-packages
           path: dist
@@ -294,7 +294,7 @@ jobs:
           mike set-default $MIKE_VERSION
 
       - name: Upload site
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: docs-site
           path: site/
@@ -384,7 +384,7 @@ jobs:
     runs-on: ubuntu-20.04
     steps:
       - name: Download distribution files
-        uses: actions/download-artifact@v3
+        uses: actions/download-artifact@v4
         with:
           name: dist-packages
           path: dist
@@ -430,7 +430,7 @@ jobs:
       id-token: write
     steps:
       - name: Download distribution files
-        uses: actions/download-artifact@v3
+        uses: actions/download-artifact@v4
         with:
           name: dist-packages
           path: dist