Update actionview requirement from >= 6, < 7.2.3 to >= 6, < 8.0.2

Updates the requirements on [actionview](https://github.com/rails/rails) to permit the latest version.
- [Release notes](https://github.com/rails/rails/releases)
- [Changelog](https://github.com/rails/rails/blob/v8.0.1/actionview/CHANGELOG.md)
- [Commits](rails/rails@v6.0.0...v7.2.2.1)

---
updated-dependencies:
- dependency-name: actionview
  dependency-type: direct:production
...

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

govspeak.gemspec

@@ -29,7 +29,7 @@ library for use in the UK Government Single Domain project'
   s.executables   = s.files.grep(%r{^bin/}) { |f| File.basename(f) }
   s.require_paths = %w[lib]
 
-  s.add_dependency "actionview", ">= 6", "< 7.2.3"
+  s.add_dependency "actionview", ">= 6", "< 8.0.2"
   s.add_dependency "addressable", ">= 2.3.8", "< 2.8.8"
   s.add_dependency "govuk_publishing_components", ">= 35.1"
   s.add_dependency "htmlentities", "~> 4"