Update ruby builder and base

[richgerrard]

Proposed changes

End of life notice: The ubi8/ruby-27 container image reaches its end of life in March 2023. Update to ubi8/ruby-30 prior to this date.

Related: https://github.com/splunk/fluent-plugin-splunk-hec/issues/257

Types of changes

What types of changes does your code introduce? Put an x in the boxes that apply

• [ ] Bugfix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ X ] Software EOL / Security patches

Checklist

Put an x in the boxes that apply.

• [ ] I have read the CONTRIBUTING doc
• [ ] I have read the CLA
• [ ] I have added tests that prove my fix is effective or that my feature works
• [ ] I have added necessary documentation (if appropriate)
• [ ] Any dependent changes have been merged and published in downstream modules