devel/rubygem-aws-sdk-mainframemodernization: Add rubygem-aws-sdk-mainframemodernization 1.0.0

Official AWS Ruby gem for AWS Mainframe Modernization.

WWW: https://github.com/aws/aws-sdk-ruby
WWW: https://github.com/aws/aws-sdk-ruby/tree/version-3/gems/aws-sdk-mainframemodernization