Update ci.yml

Author: toshimaru

.github/workflows/ci.yml

@@ -57,7 +57,7 @@ jobs:
             build-rails-versions: "5.2"
           - ruby-version: "2.7"
             build-rails-versions: "6.0,6.1"
-          - ruby-version: "2.7"
+          - ruby-version: "3.0"
             build-rails-versions: "7.0"
           - ruby-version: "3.3"
             build-rails-versions: "7.1,7.2"