Bump govuk-frontend from 5.2.0 to 5.4.0 (#753)

Bumps [govuk-frontend](https://github.com/alphagov/govuk-frontend) from 5.2.0 to 5.4.0.
- [Release notes](https://github.com/alphagov/govuk-frontend/releases)
- [Changelog](https://github.com/alphagov/govuk-frontend/blob/main/CHANGELOG.md)
- [Commits](alphagov/govuk-frontend@v5.2.0...v5.4.0)

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

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

package.json

@@ -3,6 +3,6 @@
   "private": true,
   "license": "MIT",
   "dependencies": {
-    "govuk-frontend": "^5.2.0"
+    "govuk-frontend": "^5.4.0"
   }
 }

yarn.lock

@@ -2,7 +2,7 @@
 # yarn lockfile v1
 
 
-govuk-frontend@^5.2.0:
-  version "5.2.0"
-  resolved "https://registry.npmjs.org/govuk-frontend/-/govuk-frontend-5.2.0.tgz"
-  integrity sha512-beD3wztHpkKz6JUpPwnwop1ejb4rTFMPLCutKLCIDmUS4BPpW59ggVUfctsRqHd2Zjw9wxljdRdeIJ8AZFyyTw==
+govuk-frontend@^5.4.0:
+  version "5.4.0"
+  resolved "https://registry.yarnpkg.com/govuk-frontend/-/govuk-frontend-5.4.0.tgz#8f2e0b55ef7c7552a1efe68c7b40ff1b4a393e72"
+  integrity sha512-F3YwQYrYQqIPfNxsoph6O78Ey1unCB6cy6omx8KeWY9G504lWZFBSIaiUCma1jNLw9bOUU7Ui+tXG09jjqy0Mw==