chore(deps): bump md-editor-v3 from 2.11.3 to 6.4.2 in /frontend

Bumps [md-editor-v3](https://github.com/imzbf/md-editor-v3) from 2.11.3 to 6.4.2.
- [Release notes](https://github.com/imzbf/md-editor-v3/releases)
- [Changelog](https://github.com/imzbf/md-editor-v3/blob/develop/CHANGELOG.md)
- [Commits](https://github.com/imzbf/md-editor-v3/commits/v6.4.2)

---
updated-dependencies:
- dependency-name: md-editor-v3
  dependency-version: 6.4.2
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

frontend/package.json

@@ -41,7 +41,7 @@
         "element-plus": "2.11.9",
         "js-base64": "^3.7.7",
         "jsencrypt": "^3.3.2",
-        "md-editor-v3": "^2.11.3",
+        "md-editor-v3": "^6.4.2",
         "monaco-editor": "^0.53.0",
         "nprogress": "^0.2.0",
         "pinia": "^2.1.7",