build(deps): bump katex from 0.16.10 to 0.16.21

Bumps [katex](https://github.com/KaTeX/KaTeX) from 0.16.10 to 0.16.21.
- [Release notes](https://github.com/KaTeX/KaTeX/releases)
- [Changelog](https://github.com/KaTeX/KaTeX/blob/main/CHANGELOG.md)
- [Commits](KaTeX/KaTeX@v0.16.10...v0.16.21)

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

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

Author: dependabot[bot]

Diff for: package-lock.json

@@ -37,7 +37,7 @@
     "emoji-toolkit": "^6.6.0",
     "hammerjs": "^2.0.8",
     "highlight.js": "^11.6.0",
-    "katex": "^0.16.10",
+    "katex": "^0.16.21",
     "ngx-webcam": "^0.4.1",
     "ngx-webstorage": "^18.0.0",
     "normalize.css": "^8.0.1",