Bump rubocop-ast from 1.38.1 to 1.40.0

Bumps [rubocop-ast](https://github.com/rubocop/rubocop-ast) from 1.38.1 to 1.40.0.
- [Release notes](https://github.com/rubocop/rubocop-ast/releases)
- [Changelog](https://github.com/rubocop/rubocop-ast/blob/master/CHANGELOG.md)
- [Commits](rubocop/rubocop-ast@v1.38.1...v1.40.0)

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

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

Author: dependabot[bot]

Gemfile.lock

@@ -120,7 +120,7 @@ GEM
       rubocop-ast (>= 1.38.0, < 2.0)
       ruby-progressbar (~> 1.7)
       unicode-display_width (>= 2.4.0, < 4.0)
-    rubocop-ast (1.38.1)
+    rubocop-ast (1.40.0)
       parser (>= 3.3.1.0)
     rubocop-on-rbs (1.4.2)
       rbs (~> 3.5)