Bump slimmer from 18.1.0 to 18.6.2

Bumps [slimmer](https://github.com/alphagov/slimmer) from 18.1.0 to 18.6.2.
- [Changelog](https://github.com/alphagov/slimmer/blob/main/CHANGELOG.md)
- [Commits](alphagov/slimmer@v18.1.0...v18.6.2)

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

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

Gemfile.lock

@@ -205,12 +205,11 @@ GEM
     govuk_schemas (5.0.4)
       faker (~> 3.4.1)
       json-schema (>= 2.8, < 4.4)
-    govuk_sidekiq (8.0.1)
+    govuk_sidekiq (9.0.0)
       gds-api-adapters (>= 19.1.0)
       govuk_app_config (>= 1.1)
-      redis (< 5)
-      redis-namespace (~> 1.6)
-      sidekiq (~> 6.5, >= 6.5.12)
+      redis-client (>= 0.22.2)
+      sidekiq (~> 7.0, < 8)
     govuk_test (4.1.0)
       brakeman (>= 5.0.2)
       capybara (>= 3.36)
@@ -241,6 +240,7 @@ GEM
     listen (3.9.0)
       rb-fsevent (~> 0.10, >= 0.10.3)
       rb-inotify (~> 0.9, >= 0.9.10)
+    logger (1.6.1)
     logstasher (2.1.5)
       activesupport (>= 5.2)
       request_store
@@ -257,7 +257,7 @@ GEM
     method_source (1.1.0)
     mime-types (3.5.2)
       mime-types-data (~> 3.2015)
-    mime-types-data (3.2024.0820)
+    mime-types-data (3.2024.0903)
     mini_mime (1.1.5)
     mini_portile2 (2.8.7)
     minitest (5.25.1)
@@ -534,19 +534,19 @@ GEM
     puma (6.4.3)
       nio4r (~> 2.0)
     racc (1.8.1)
-    rack (2.2.9)
-    rack-protection (3.2.0)
+    rack (3.1.7)
+    rack-protection (4.0.0)
       base64 (>= 0.1.0)
-      rack (~> 2.2, >= 2.2.4)
+      rack (>= 3.0.0, < 4)
     rack-proxy (0.7.7)
       rack
-    rack-session (1.0.2)
-      rack (< 3)
+    rack-session (2.0.0)
+      rack (>= 3.0.0)
     rack-test (2.1.0)
       rack (>= 1.3)
-    rackup (1.0.0)
-      rack (< 3)
-      webrick
+    rackup (2.1.0)
+      rack (>= 3)
+      webrick (~> 1.8)
     rails (7.1.4)
       actioncable (= 7.1.4)
       actionmailbox (= 7.1.4)
@@ -587,9 +587,8 @@ GEM
       ffi (~> 1.0)
     rdoc (6.7.0)
       psych (>= 4.0.0)
-    redis (4.8.1)
-    redis-namespace (1.11.0)
-      redis (>= 4)
+    redis-client (0.22.2)
+      connection_pool
     regexp_parser (2.9.2)
     reline (0.5.10)
       io-console (~> 0.5)
@@ -684,22 +683,24 @@ GEM
     sentry-sidekiq (5.19.0)
       sentry-ruby (~> 5.19.0)
       sidekiq (>= 3.0)
-    sidekiq (6.5.12)
-      connection_pool (>= 2.2.5, < 3)
-      rack (~> 2.0)
-      redis (>= 4.5.0, < 5)
+    sidekiq (7.3.2)
+      concurrent-ruby (< 2)
+      connection_pool (>= 2.3.0)
+      logger
+      rack (>= 2.2.4)
+      redis-client (>= 0.22.2)
     simplecov (0.22.0)
       docile (~> 1.1)
       simplecov-html (~> 0.11)
       simplecov_json_formatter (~> 0.1)
     simplecov-html (0.12.3)
     simplecov_json_formatter (0.1.4)
-    slimmer (18.1.0)
+    slimmer (18.6.2)
       json
       nokogiri (~> 1.7)
       null_logger
       plek (>= 1.1.0)
-      rack
+      rack (>= 3.0)
       rest-client
     snaky_hash (2.0.1)
       hashie