feat: block non-semantic, neutral text classes

[briangregoryholmes]

Summary

This PR adds a custom eslint rule that checks for usage of neutral, zinc, slate, stone and gray Tailwind colors in text- prefixed utility classes. It also adds these potential classes to the Tailwind config blocklist so that they aren't generated to begin with.

To comply with the new rule, this PR also removes any remaining classes that followed this pattern.

Checklist:

• Covered by tests
• Ran it and it works as intended
• Reviewed the diff before requesting a review
• Checked for unhandled edge cases
• Linked the issues it closes
• Checked if the docs need to be updated. If so, create a separate Linear DOCS issue
• Intend to cherry-pick into the release branch
• I'm proud of this work!