Bump actions/upload-artifact from 4 to 5

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 4 to 5.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v4...v5)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/docs.yml

@@ -42,7 +42,7 @@ jobs:
                     docker-version: ${{ env.BUILDER_VERSION }}
 
             -   name: Upload artifacts
-                uses: actions/upload-artifact@v4
+                uses: actions/upload-artifact@v5
                 with:
                     name: docs
                     path: |
@@ -51,7 +51,7 @@ jobs:
                     retention-days: 7
 
             -   name: Upload search indexes
-                uses: actions/upload-artifact@v4
+                uses: actions/upload-artifact@v5
                 with:
                     name: ${{ env.ARTIFACT_INDEXES }}
                     path: artifacts/${{ env.ALGOLIA_ARTIFACT }}
@@ -89,7 +89,7 @@ jobs:
                     echo "Sitemap: https://${{ env.DOMAIN_NAME }}/sitemap.xml" >> robots.txt
 
             -   name: Upload artifacts
-                uses: actions/upload-artifact@v4
+                uses: actions/upload-artifact@v5
                 with:
                     name: robots
                     path: robots.txt