Bump rbs from 3.8.1 to 3.9.0

Bumps [rbs](https://github.com/ruby/rbs) from 3.8.1 to 3.9.0.
- [Release notes](https://github.com/ruby/rbs/releases)
- [Changelog](https://github.com/ruby/rbs/blob/master/CHANGELOG.md)
- [Commits](ruby/rbs@v3.8.1...v3.9.0)

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

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

Author: dependabot[bot]

Gemfile.lock

@@ -10,11 +10,11 @@ GEM
   remote: https://rubygems.org/
   specs:
     docile (1.4.0)
-    logger (1.6.4)
+    logger (1.6.6)
     minitest (5.25.5)
     prettier_print (1.2.1)
     rake (13.2.1)
-    rbs (3.8.1)
+    rbs (3.9.0)
       logger
     simplecov (0.22.0)
       docile (~> 1.1)