Bump rubocop-govuk from 4.8.0 to 4.9.0

Bumps [rubocop-govuk](https://github.com/alphagov/rubocop-govuk) from 4.8.0 to 4.9.0.
- [Release notes](https://github.com/alphagov/rubocop-govuk/releases)
- [Changelog](https://github.com/alphagov/rubocop-govuk/blob/main/CHANGELOG.md)
- [Commits](alphagov/rubocop-govuk@v4.8.0...v4.9.0)

---
updated-dependencies:
- dependency-name: rubocop-govuk
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Gemfile.lock

@@ -217,7 +217,7 @@ GEM
       racc (~> 1.4)
     null_logger (0.0.1)
     parallel (1.22.1)
-    parser (3.1.2.1)
+    parser (3.1.3.0)
       ast (~> 2.4.1)
     plek (4.1.0)
     prometheus_exporter (2.0.5)
@@ -276,7 +276,7 @@ GEM
     rainbow (3.1.1)
     raindrops (0.20.0)
     rake (13.0.6)
-    regexp_parser (2.6.0)
+    regexp_parser (2.6.1)
     request_store (1.5.1)
       rack (>= 1.4)
     rest-client (2.1.0)
@@ -288,7 +288,7 @@ GEM
     rouge (4.0.0)
     rss (0.2.9)
       rexml
-    rubocop (1.37.1)
+    rubocop (1.39.0)
       json (~> 2.3)
       parallel (~> 1.10)
       parser (>= 3.1.2.1)
@@ -300,19 +300,19 @@ GEM
       unicode-display_width (>= 1.4.0, < 3.0)
     rubocop-ast (1.23.0)
       parser (>= 3.1.1.0)
-    rubocop-govuk (4.8.0)
-      rubocop (= 1.37.1)
+    rubocop-govuk (4.9.0)
+      rubocop (= 1.39.0)
       rubocop-ast (= 1.23.0)
-      rubocop-rails (= 2.17.1)
+      rubocop-rails (= 2.17.3)
       rubocop-rake (= 0.6.0)
-      rubocop-rspec (= 2.14.1)
-    rubocop-rails (2.17.1)
+      rubocop-rspec (= 2.15.0)
+    rubocop-rails (2.17.3)
       activesupport (>= 4.2.0)
       rack (>= 1.1)
       rubocop (>= 1.33.0, < 2.0)
     rubocop-rake (0.6.0)
       rubocop (~> 1.0)
-    rubocop-rspec (2.14.1)
+    rubocop-rspec (2.15.0)
       rubocop (~> 1.33)
     ruby-progressbar (1.11.0)
     ruby2_keywords (0.0.5)