Get Ruby 3.1 in CI

Author: petergoldstein

.github/workflows/ci.yml

@@ -30,6 +30,10 @@ jobs:
       matrix:
        include:
          # Edge Rails (7.1) builds >= 2.7
+         - ruby: 3.1
+           allow_failure: true
+           env:
+             RAILS_VERSION: 'main'
          - ruby: '3.0'
            allow_failure: true
            env:
@@ -41,19 +45,19 @@ jobs:
 
          # Rails 7.0 builds >= 2.7
          - ruby: 3.1
-           allow_failure: true
            env:
              RAILS_VERSION: '~> 7.0.0'
          - ruby: '3.0'
-           allow_failure: true
            env:
              RAILS_VERSION: '~> 7.0.0'
          - ruby: 2.7
-           allow_failure: true
            env:
              RAILS_VERSION: '~> 7.0.0'
 
          # Rails 6.1 builds >= 2.5
+         - ruby: 3.1
+           env:
+             RAILS_VERSION: '~> 6.1.0'
          - ruby: '3.0'
            env:
              RAILS_VERSION: '~> 6.1.0'