[CI] Upgrade to eslint v9

[Siddhi-sahu]

Description

This PR fixes #6891

Notes for Reviewers

Initial migration using :

1. npx @eslint/migrate-config .eslintrc.js
2. npm install globals @eslint/js @eslint/eslintrc -D
3. npm install eslint@latest -D

My Previous attempt on migrating eslint to v9, resulted in this error during the build:

i resolved this issue by the following:

1. npm install --save-dev gatsby-plugin-eslint eslint eslint-webpack-plugin eslint-config-react-app
2. creating an empty .eslintrc.js file in the root dir (this prevents Gatsby internal eslint loader trying to use the deprecated options)

The sites builds normal now:

checks:

No problem with Husky pre-commit hook inside the devcontainer:

Signed commits

• Yes, I signed my commits.

[l5io]

🚀 Preview for commit e07ca5e at: https://6912c08f5ef5199b76af14d8--layer5.netlify.app

[Rajesh-Nagarajan-11]

✖ 86 problems (78 errors, 8 warnings) in eslint

[l5io]

🚀 Preview for commit cf2f4fa at: https://6912c49f8ec7bf44bcf6f6d4--layer5.netlify.app

[Rajesh-Nagarajan-11]

Why don't you delete that ?

[Siddhi-sahu]

to disable gatsby in-built eslint loader. Read here:

https://www.gatsbyjs.com/docs/how-to/custom-configuration/eslint/#:~:text=Creating%20an%20empty%20.eslintrc%20file%20at%20the%20root%20of%20your%20project%20will%20mostly%20disable%20ESLint%20for%20your%20site.%20The%20empty%20file%20will%20disable%20the%20built%2Din%20eslint%2Dloader%20because%20Gatsby%20assumes%20once%20you%20have%20an%20ESLint%20file%20you%20are%20in%20charge%20of%20linting

[Rajesh-Nagarajan-11]

In this file you just fixed trailing spaces right ?

[Siddhi-sahu]

yes, eslint did that.

[Rajesh-Nagarajan-11]

Looks Good !! Thanks himani 🫶

[KatalKavya96]

Looks good to me!

[l5io]

🚀 Preview for commit 73a9e85 at: https://691497e5443f0e30daa723f6--layer5.netlify.app