Clean up RuboCop configuration after Ruby and Rails upgrade

What does this MR do and why?

This MR cleans up some configuration and removes a CI job.

We no longer support Ruby 2.7 and upgraded to Rails 7 lately.

With that, we can:

• Remove some Ruby specific RuboCop configurations
• Target Rails Version 7.0
• Disable and remove Lint/LastKeywordArgument cop rule
• Remove related CI job

Closes #389422 (closed)

MR acceptance checklist

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