Bump govuk_publishing_components from 28.7.1 to 28.8.1

Bumps [govuk_publishing_components](https://github.com/alphagov/govuk_publishing_components) from 28.7.1 to 28.8.1.
- [Release notes](https://github.com/alphagov/govuk_publishing_components/releases)
- [Changelog](https://github.com/alphagov/govuk_publishing_components/blob/master/CHANGELOG.md)
- [Commits](alphagov/govuk_publishing_components@v28.7.1...v28.8.1)

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

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

Author: dependabot[bot]

Gemfile.lock

@@ -120,12 +120,11 @@ GEM
     govuk_personalisation (0.11.2)
       plek (>= 1.9.0)
       rails (>= 6, < 8)
-    govuk_publishing_components (28.7.1)
+    govuk_publishing_components (28.8.1)
       govuk_app_config
       govuk_personalisation (>= 0.7.0)
       kramdown
       plek
-      psych (>= 4)
       rails (>= 6)
       rouge
       sprockets (< 4)
@@ -208,8 +207,6 @@ GEM
     pry (0.13.1)
       coderay (~> 1.1)
       method_source (~> 1.0)
-    psych (4.0.3)
-      stringio
     public_suffix (4.0.6)
     puma (5.6.2)
       nio4r (~> 2.0)
@@ -339,7 +336,6 @@ GEM
       activesupport (>= 5.2)
       sprockets (>= 3.0.0)
     statsd-ruby (1.5.0)
-    stringio (3.0.1)
     terminal-table (3.0.2)
       unicode-display_width (>= 1.1.1, < 3)
     thor (1.2.1)