Bump rubocop-ast from 1.28.0 to 1.28.1 (#192)

Bumps [rubocop-ast](https://github.com/rubocop/rubocop-ast) from 1.28.0 to 1.28.1.
- [Release notes](https://github.com/rubocop/rubocop-ast/releases)
- [Changelog](https://github.com/rubocop/rubocop-ast/blob/master/CHANGELOG.md)
- [Commits](rubocop/rubocop-ast@v1.28.0...v1.28.1)

---
updated-dependencies:
- dependency-name: rubocop-ast
  dependency-type: indirect
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Gemfile.lock

@@ -35,7 +35,7 @@ GEM
       rubocop-ast (>= 1.28.0, < 2.0)
       ruby-progressbar (~> 1.7)
       unicode-display_width (>= 2.4.0, < 3.0)
-    rubocop-ast (1.28.0)
+    rubocop-ast (1.28.1)
       parser (>= 3.2.1.0)
     rubocop-minitest (0.30.0)
       rubocop (>= 1.39, < 2.0)