Bump mermaid and ngx-markdown

Bumps [mermaid](https://github.com/mermaid-js/mermaid) to 11.3.0 and updates ancestor dependency [ngx-markdown](https://github.com/jfcere/ngx-markdown). These dependencies need to be updated together.


Updates `mermaid` from 9.3.0 to 11.3.0
- [Release notes](https://github.com/mermaid-js/mermaid/releases)
- [Changelog](https://github.com/mermaid-js/mermaid/blob/develop/CHANGELOG.md)
- [Commits](https://github.com/mermaid-js/mermaid/compare/[email protected])

Updates `ngx-markdown` from 16.0.0 to 18.1.0
- [Release notes](https://github.com/jfcere/ngx-markdown/releases)
- [Commits](jfcere/ngx-markdown@v16.0.0...v18.1.0)

---
updated-dependencies:
- dependency-name: mermaid
  dependency-type: indirect
- dependency-name: ngx-markdown
  dependency-type: direct:production
...

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