chore(deps): update steep requirement from ~> 1.7.0 to ~> 1.9.3

Updates the requirements on [steep](https://github.com/soutaro/steep) to permit the latest version.
- [Release notes](https://github.com/soutaro/steep/releases)
- [Changelog](https://github.com/soutaro/steep/blob/master/CHANGELOG.md)
- [Commits](soutaro/steep@v1.7.0...v1.9.3)

---
updated-dependencies:
- dependency-name: steep
  dependency-type: direct:production
...

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

Gemfile

@@ -10,6 +10,6 @@ gem 'parallel_tests'
 gem 'rake', '~> 13.0'
 gem 'rubocop', '1.70.0'
 gem 'simplecov'
-gem 'steep', '~> 1.7.0'
+gem 'steep', '~> 1.9.3'
 gem 'webmock', '~> 3.24.0'
 gem 'yard', '~> 0.9.11'