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/workflow.yml

@@ -1,4 +1,4 @@
-name: MjmlVisualizer
+name: MjmlVisualizer
 
 on:
   push:
@@ -30,7 +30,7 @@ jobs:
         run: dotnet publish -p:Version=${{ env.version }}
 
       - name: Publish Build Artifacts
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: MjmlVisualizer
           path: |