Rails 7.2 support (#242)

* Rails 7.2 support

* Update to Bot API 7.9

.github/workflows/ci.yml

@@ -26,6 +26,8 @@ jobs:
           - gemfiles/rails_51.gemfile
         include:
           # ruby 3.x
+          - ruby: '3.2'
+            gemfile: gemfiles/rails_72.gemfile
           - ruby: '3.2'
             gemfile: gemfiles/rails_71.gemfile
           - ruby: '3.0'