chore(deps-dev): bump @typescript-eslint/eslint-plugin (#163)

Bumps [@typescript-eslint/eslint-plugin](https://github.com/typescript-eslint/typescript-eslint/tree/HEAD/packages/eslint-plugin) from 4.20.0 to 4.21.0.
- [Release notes](https://github.com/typescript-eslint/typescript-eslint/releases)
- [Changelog](https://github.com/typescript-eslint/typescript-eslint/blob/master/packages/eslint-plugin/CHANGELOG.md)
- [Commits](https://github.com/typescript-eslint/typescript-eslint/commits/v4.21.0/packages/eslint-plugin)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Federico Grandi <fgrandi30@gmail.com>

package.json

@@ -38,7 +38,7 @@
   "devDependencies": {
     "@types/js-yaml": "^4.0.0",
     "@types/node": "^12.12.54",
-    "@typescript-eslint/eslint-plugin": "^4.20.0",
+    "@typescript-eslint/eslint-plugin": "^4.21.0",
     "@typescript-eslint/parser": "^4.21.0",
     "@vercel/ncc": "^0.28.2",
     "all-contributors-cli": "^6.20.0",