Bump actions/upload-artifact from 6 to 7

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 6 to 7.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v6...v7)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/continuous-deployment.yaml

@@ -133,7 +133,7 @@ jobs:
 
       - id: save
         name: Save artifact
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         with:
           name: release-candidate
           path: ./dist

.github/workflows/docs.yaml

@@ -39,7 +39,7 @@ jobs:
 
       - id: upload-release-candidate
         name: Upload release candidate
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         with:
           name: release-candidate
           path: ./_build/html/