github: bump to upload/download artifact v4

Author: jnikula

.github/workflows/deploy.yaml

@@ -10,7 +10,7 @@ jobs:
       - uses: actions/setup-python@v4
       - run: pip install sphinx
       - run: sphinx-build docs _build
-      - uses: actions/upload-artifact@v3
+      - uses: actions/upload-artifact@v4
         with:
           name: docs-artifact
           path: _build
@@ -34,7 +34,7 @@ jobs:
           node-version: '16'
       - run: npm install
       - run: npm run build
-      - uses: actions/upload-artifact@v3
+      - uses: actions/upload-artifact@v4
         with:
           name: ${{ matrix.name }}
           path: dist
@@ -50,15 +50,15 @@ jobs:
       name: github-pages
       url: ${{steps.deployment.outputs.page_url}}
     steps:
-      - uses: actions/download-artifact@v3
+      - uses: actions/download-artifact@v4
         with:
           name: app-testing
           path: testing
-      - uses: actions/download-artifact@v3
+      - uses: actions/download-artifact@v4
         with:
           name: app-stable
           path: stable
-      - uses: actions/download-artifact@v3
+      - uses: actions/download-artifact@v4
         with:
           name: docs-artifact
           path: .