CI: Add JRuby 10 testing

Author: bastelfreak

.github/workflows/tests.yaml

@@ -48,6 +48,7 @@ jobs:
           - {os: ubuntu-24.04, ruby: 'jruby-9.4'}
           - {os: ubuntu-24.04, ruby: 'jruby-9.4.8.0'}
           - {os: ubuntu-24.04, ruby: 'jruby-9.4.13.0'}
+          - {os: ubuntu-24.04, ruby: 'jruby-10'}
           - {os: windows-2025, ruby: '3.1'}
           - {os: windows-2025, ruby: '3.2'} # openssl 3
           - {os: windows-2025, ruby: '3.3'} # openssl 3