build(deps): bump govuk-frontend from 5.4.0 to 5.6.0

Bumps [govuk-frontend](https://github.com/alphagov/govuk-frontend) from 5.4.0 to 5.6.0.
- [Release notes](https://github.com/alphagov/govuk-frontend/releases)
- [Changelog](https://github.com/alphagov/govuk-frontend/blob/main/CHANGELOG.md)
- [Commits](alphagov/govuk-frontend@v5.4.0...v5.6.0)

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

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

package.json

@@ -29,7 +29,7 @@
     "@turf/union": "^7.0.0",
     "accessible-autocomplete": "^2.0.4",
     "file-saver": "^2.0.5",
-    "govuk-frontend": "^5.4.0",
+    "govuk-frontend": "^5.6.0",
     "jspdf": "^2.5.1",
     "lit": "^3.0.1",
     "ol": "^9.1.0",