Add missing C8G / M8G EC2 Instance Types

[albertoal]

Adding missing C8G / M8G Instance types

When configuring a Agent, R8G is present but not M8G or C8G which were launched at the same time

Available C8G Instance types and specs https://aws.amazon.com/ec2/instance-types/c8g/
Available M8G Instance types and specs https://aws.amazon.com/ec2/instance-types/m8g/

Testing done

Submitter checklist

• Make sure you are opening from a topic/feature/bugfix branch (right side) and not your main branch!
• Ensure that the pull request title represents the desired changelog entry
• Please describe what you did
• Link to relevant issues in GitHub or Jira
• Link to relevant pull requests, esp. upstream and downstream changes
• Ensure you have provided tests that demonstrate the feature works or the issue is fixed

[albertoal]

@basil @res0nance do you mind taking a look? I believe this is related to #1065 which you worked on recently. I believe that with the SDK v2 migration maintaining this list will be redundant, but in the meantime, it will be great for the plugin to support M8G / C8G as it supports R8G today. Thanks!

[basil]

Thanks for the PR! Does it work?

[albertoal]

@basil all the ci.jenkins.io tests passed which is a good sign, but I'm happy to build the plugin locally and run it on a local Docker Jenkins instance. Are there local testing steps published somewhere? I can give it a go and report back. Thanks!

[jglick]

Are there local testing steps published somewhere?

If your dev machine is authorized to make EC2 API requests, simply make sure you have Java and Maven installed and run

mvn hpi:run

to test your changes.