Update shoulda-matchers requirement from ~> 6.0 to ~> 7.0

Updates the requirements on [shoulda-matchers](https://github.com/thoughtbot/shoulda-matchers) to permit the latest version.
- [Release notes](https://github.com/thoughtbot/shoulda-matchers/releases)
- [Changelog](https://github.com/thoughtbot/shoulda-matchers/blob/main/CHANGELOG.md)
- [Commits](thoughtbot/shoulda-matchers@v6.0.0...v7.0.1)

---
updated-dependencies:
- dependency-name: shoulda-matchers
  dependency-version: 7.0.1
  dependency-type: direct:development
...

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

Author: dependabot[bot]

alchemy_cms.gemspec

@@ -69,7 +69,7 @@ Gem::Specification.new do |gem|
   gem.add_development_dependency "simplecov", ["~> 0.20"]
   gem.add_development_dependency "selenium-webdriver", ["~> 4.10"]
   gem.add_development_dependency "webmock", ["~> 3.3"]
-  gem.add_development_dependency "shoulda-matchers", ["~> 6.0"]
+  gem.add_development_dependency "shoulda-matchers", "~> 7.0"
   gem.add_development_dependency "timecop", ["~> 0.9"]
 
   gem.post_install_message = <<~MSG