Bump slimmer from 18.5.0 to 18.5.2

Bumps [slimmer](https://github.com/alphagov/slimmer) from 18.5.0 to 18.5.2.
- [Changelog](https://github.com/alphagov/slimmer/blob/main/CHANGELOG.md)
- [Commits](alphagov/slimmer@v18.5.0...v18.5.2)

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

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

Author: dependabot[bot]

Gemfile.lock

@@ -248,7 +248,7 @@ GEM
       net-protocol
     netrc (0.11.0)
     nio4r (2.7.3)
-    nokogiri (1.16.5)
+    nokogiri (1.16.6)
       mini_portile2 (~> 2.8.2)
       racc (~> 1.4)
     null_logger (0.0.1)
@@ -479,7 +479,7 @@ GEM
     puma (6.4.2)
       nio4r (~> 2.0)
     racc (1.8.0)
-    rack (3.1.0)
+    rack (3.1.3)
     rack-proxy (0.7.7)
       rack
     rack-session (2.0.0)
@@ -614,7 +614,7 @@ GEM
       simplecov_json_formatter (~> 0.1)
     simplecov-html (0.12.3)
     simplecov_json_formatter (0.1.4)
-    slimmer (18.5.0)
+    slimmer (18.5.2)
       json
       nokogiri (~> 1.7)
       null_logger