Upgrade eslint to v9

[IAM5K]

Title: 🔼 Upgrade ESLint to Version 9 (v8 is deprecated)

Description:

ESLint v8 is now deprecated, and we should upgrade to ESLint v9 to stay current with the latest linting features, bug fixes, and security updates. Keeping our tooling up-to-date also helps prevent compatibility issues with other modern libraries and plugins.

Tasks:

• Upgrade ESLint to v9 in package.json
• Update any related ESLint plugins and configs to ensure compatibility with v9
• Review and resolve any new linting rules or breaking changes introduced in v9
• Test the codebase to ensure no linting or build issues occur post-upgrade

Resources:

• ESLint v9 Migration Guide
• Release Notes

Priority: Medium (but should be addressed soon due to deprecation)

Impact: Developer experience, long-term maintainability