fix: correctly handle number values in config

[patrikholcak]

Feel free to edit/close/etc.

Pull Request Name

Correctly handle number values in config.

Description

Given this Tailwind config:

module.exports = {
  theme: {
      zIndex: {
        dialog: 10000,
      },
  }
}

The lint task fails with

TypeError: Error while loading rule 'tailwindcss/no-contradicting-classname': val.indexOf is not a function

Type of change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Test is included in the PR

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• [-] I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have checked my code and corrected any misspellings

[francoismassart]

@patrikholcak Thank you for contributing 😉