Upgrade: Bump esbuild from 0.19.12 to 0.21.4

Bumps [esbuild](https://github.com/evanw/esbuild) from 0.19.12 to 0.21.4.
- [Release notes](https://github.com/evanw/esbuild/releases)
- [Changelog](https://github.com/evanw/esbuild/blob/main/CHANGELOG.md)
- [Commits](evanw/esbuild@v0.19.12...v0.21.4)

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

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

package.json

@@ -28,7 +28,7 @@
     "@types/node": "^14.18.54",
     "@vuepress/plugin-pwa": "^1.9.9",
     "cross-spawn": "^7.0.3",
-    "esbuild": "^0.19.3",
+    "esbuild": "^0.21.4",
     "eslint": "^8.46.0",
     "fs-extra": "^10.1.0",
     "mocha": "^10.4.0",