Update activerecord requirement from >= 7.0, < 8 to >= 7.0, < 9

Updates the requirements on [activerecord](https://github.com/rails/rails) to permit the latest version.
- [Release notes](https://github.com/rails/rails/releases)
- [Changelog](https://github.com/rails/rails/blob/v8.0.0/activerecord/CHANGELOG.md)
- [Commits](rails/rails@v7.0.0...v7.2.2)

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

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

anony.gemspec

@@ -38,7 +38,7 @@ Gem::Specification.new do |spec|
     spec.add_dependency "activerecord", "~> #{ENV['RAILS_VERSION']}"
     spec.add_dependency "activesupport", "~> #{ENV['RAILS_VERSION']}"
   else
-    spec.add_dependency "activerecord", ">= 7.0", "< 8"
+    spec.add_dependency "activerecord", ">= 7.0", "< 9"
     spec.add_dependency "activesupport", ">= 7.0", "< 8"
   end
   spec.metadata["rubygems_mfa_required"] = "true"