Removed Rails 5.2, 6.0 test

Author: huacnlee

.github/workflows/build.yml

@@ -34,12 +34,6 @@ jobs:
           - ruby: 2.7
             gemfile: gemfiles/Gemfile-6-1
             rails_version: 6.1
-          - ruby: 2.6
-            gemfile: gemfiles/Gemfile-6-0
-            rails_version: 6.0
-          - ruby: 2.6
-            gemfile: gemfiles/Gemfile-5-2
-            rails_version: 5.0
 
     env:
       BUNDLE_GEMFILE: ${{ matrix.gemfile }}