Upgrade: Bump esbuild from 0.20.0 to 0.21.0

Bumps [esbuild](https://github.com/evanw/esbuild) from 0.20.0 to 0.21.0.
- [Release notes](https://github.com/evanw/esbuild/releases)
- [Changelog](https://github.com/evanw/esbuild/blob/main/CHANGELOG.md)
- [Commits](https://github.com/evanw/esbuild/compare/v0.20.0...v0.21.0)

---
updated-dependencies:
- dependency-name: esbuild
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

package.json

@@ -37,7 +37,7 @@
     "@vueuse/core": "^10.9.0",
     "anywhere": "^1.6.0",
     "bootstrap": "^5.2.0",
-    "esbuild": "^0.20.0",
+    "esbuild": "^0.21.0",
     "jquery": "^3.6.0",
     "markdown-it-footnote": "^4.0.0",
     "mermaid": "^10.9.0",