Bump esbuild and vitest in /frontend

Bumps [esbuild](https://github.com/evanw/esbuild) and [vitest](https://github.com/vitest-dev/vitest/tree/HEAD/packages/vitest). These dependencies needed to be updated together.

Updates `esbuild` from 0.24.2 to 0.27.3
- [Release notes](https://github.com/evanw/esbuild/releases)
- [Changelog](https://github.com/evanw/esbuild/blob/main/CHANGELOG-2024.md)
- [Commits](https://github.com/evanw/esbuild/compare/v0.24.2...v0.27.3)

Updates `vitest` from 2.1.9 to 4.0.18
- [Release notes](https://github.com/vitest-dev/vitest/releases)
- [Commits](https://github.com/vitest-dev/vitest/commits/v4.0.18/packages/vitest)

---
updated-dependencies:
- dependency-name: esbuild
  dependency-version: 0.27.3
  dependency-type: direct:development
- dependency-name: vitest
  dependency-version: 4.0.18
  dependency-type: direct:development
...

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

frontend/package.json

@@ -11,8 +11,8 @@
   },
   "devDependencies": {
     "@types/leaflet": "^1.9.0",
-    "esbuild": "^0.24.0",
+    "esbuild": "^0.27.3",
     "typescript": "^5.7.0",
-    "vitest": "^2.1.0"
+    "vitest": "^4.0.18"
   }
 }