CI: drop unsupported jruby versions

Reference:
https://github.com/ruby/setup-ruby?tab=readme-ov-file#supported-versions

Author: skrobul

.github/workflows/ruby.yml

@@ -33,8 +33,7 @@ jobs:
         - '3.0'
         - '3.1'
         - jruby-9.1.17.0
-        - jruby-9.2.21.0
-        - jruby-9.3.6.0
+        - jruby-10.0.2.0
 
     steps:
     - uses: actions/checkout@v3