Feat(web): Add ESlint rule to prevent use of 'process.env' within the source code.

[sharma-shanu]

Since we are using 't3-env' to support typesafe environment variables across the web app.

This PR adds an ESlint rule in the apps/web project to avoid the direct access of environment variables in the source code.

During Development:

After npm run lint:

[vercel[bot]]

Someone is attempting to deploy a commit to the Inbox Zero Team on Vercel.

A member of the Team first needs to authorize it.

[elie222]

Nice 😄