Use 3.0.2 instead of 3.0.3

Author: rafaelfranca

.github/workflows/ci.yml

@@ -6,7 +6,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: [ '2.7', '3.0', 'head' ]
+        ruby: [ '2.7', '3.0.2', 'head' ]
         rails: [ '6.0', '6.1', 'edge' ]
         include:
           - ruby: '2.6'