chore: add ruby 3

Author: bibendi

.github/workflows/ruby.yml

@@ -12,7 +12,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: [ '2.6', '2.7' ]
+        ruby: [ '2.6', '2.7', '3.0' ]
     env:
       RUBY_IMAGE: ${{ matrix.ruby }}
     name: Ruby ${{ matrix.ruby }}