build(deps): bump actions/upload-artifact from 4 to 6

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 4 to 6.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v4...v6)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/deploy-docs.yml

@@ -47,7 +47,7 @@ jobs:
           DOCS_VERSION: v3
 
       - name: Upload v3 artifact
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: docs-v3
           path: ./docs/.output/public
@@ -81,7 +81,7 @@ jobs:
           DOCS_VERSION: v2
 
       - name: Upload v2 artifact
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: docs-v2
           path: ./docs/.output/public