Bump mermaid from 8.13.4 to 8.13.8 (go-gitea#18198)

Bumps [mermaid](https://github.com/knsv/mermaid) from 8.13.4 to 8.13.8.
- [Release notes](https://github.com/knsv/mermaid/releases)
- [Changelog](https://github.com/mermaid-js/mermaid/blob/develop/docs/CHANGELOG.md)
- [Commits](mermaid-js/mermaid@8.13.4...8.13.8)

---
updated-dependencies:
- dependency-name: mermaid
  dependency-type: direct:production
...

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

package.json

@@ -22,7 +22,7 @@
     "less": "4.1.2",
     "less-loader": "10.2.0",
     "license-checker-webpack-plugin": "0.2.1",
-    "mermaid": "8.13.4",
+    "mermaid": "8.13.8",
     "mini-css-extract-plugin": "2.4.5",
     "monaco-editor": "0.30.1",
     "monaco-editor-webpack-plugin": "6.0.0",