build(deps): bump mermaid and @kangc/v-md-editor

Removes [mermaid](https://github.com/mermaid-js/mermaid). It's no longer used after updating ancestor dependency [@kangc/v-md-editor](https://github.com/code-farmer-i/vue-markdown-editor). These dependencies need to be updated together.


Removes `mermaid`

Updates `@kangc/v-md-editor` from 1.7.11 to 2.1.7
- [Release notes](https://github.com/code-farmer-i/vue-markdown-editor/releases)
- [Changelog](https://github.com/code-farmer-i/vue-markdown-editor/blob/dev/docs/changelog.md)
- [Commits](code-farmer-i/vue-markdown-editor@v1.7.11...v2.1.7)

---
updated-dependencies:
- dependency-name: mermaid
  dependency-type: indirect
- dependency-name: "@kangc/v-md-editor"
  dependency-type: direct:production
...

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