build(deps): bump katex from 0.16.11 to 0.16.21

Bumps [katex](https://github.com/KaTeX/KaTeX) from 0.16.11 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@v0.16.11...v0.16.21)

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

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

apps/renderer/package.json

@@ -66,7 +66,7 @@
     "idb-keyval": "6.2.1",
     "immer": "10.1.1",
     "jotai": "2.10.3",
-    "katex": "0.16.11",
+    "katex": "0.16.21",
     "lethargy": "1.0.9",
     "masonic": "4.0.1",
     "mdast-util-gfm-table": "^2.0.0",