Remove EOL Ruby/Rails versions from CI matrix

Author: shioyama

.github/workflows/ci.yml

@@ -19,16 +19,11 @@ jobs:
         ruby:
           - '3.3'
           - '3.2'
-          - '3.1'
         database:
           - 'sqlite3'
           - 'mysql'
           - 'postgres'
         orm:
-          - name: 'active_record'
-            version: '7.0'
-          - name: 'active_record'
-            version: '7.1'
           - name: 'active_record'
             version: '7.2'
           - name: 'active_record'