Use a very large limit for RuboCop cache

What does this MR do and why?

Use a very large limit for RuboCop cache

Because we rebuild the whole cache every 2 hours on CI anyway, and locally it does need a larger limit when we're switching between branches.

Given that we'll not have so many files, we no longer need to check if the limit is large enough.

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How to set up and validate locally

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MR acceptance checklist

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Related to #371856 (closed)