Bump activesupport from 8.1.2 to 8.1.2.1 in /steep

Bumps [activesupport](https://github.com/rails/rails) from 8.1.2 to 8.1.2.1.
- [Release notes](https://github.com/rails/rails/releases)
- [Changelog](https://github.com/rails/rails/blob/v8.1.2.1/activesupport/CHANGELOG.md)
- [Commits](rails/rails@v8.1.2...v8.1.2.1)

---
updated-dependencies:
- dependency-name: activesupport
  dependency-version: 8.1.2.1
  dependency-type: indirect
...

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

Author: dependabot[bot]

steep/Gemfile.lock

@@ -1,7 +1,7 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    activesupport (8.1.2)
+    activesupport (8.1.2.1)
       base64
       bigdecimal
       concurrent-ruby (~> 1.0, >= 1.3.1)