build(deps): bump prettier from 2.3.2 to 2.4.0 in /web

Bumps [prettier](https://github.com/prettier/prettier) from 2.3.2 to 2.4.0.
- [Release notes](https://github.com/prettier/prettier/releases)
- [Changelog](https://github.com/prettier/prettier/blob/main/CHANGELOG.md)
- [Commits](https://github.com/prettier/prettier/compare/2.3.2...2.4.0)

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

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

web/package.json

@@ -18,7 +18,7 @@
     "eslint-plugin-prettier": "^3.4.1",
     "less": "^4.1.1",
     "less-loader": "^7.3.0",
-    "prettier": "^2.3.2",
+    "prettier": "^2.4.0",
     "react": "^17.0.2",
     "react-app-rewired": "^2.1.8",
     "react-dom": "^17.0.2",