chore: remove eslint-env configuration comment

[MikeMcC399]

Situation

scripts/set-port.js includes the ESLint configuration comment:

/* eslint-env node */

This is no longer used in ESLint flat configurations, and will cause an error in ESLint 10.x.

See Configuration Migration Guide eslint-env Configuration Comments which says:

... when migrating from eslintrc to flat config, eslint-env configuration comments should be removed from all files.

This repo is already using an ESLint 9.x flat configuration.

Change

Remove the unused eslint-env configuration comment from scripts/set-port.js.

Verification

npm ci
npx eslint

Confirm no errors reported.

[cypress-app-bot]

• Create a Draft Pull Request if your PR is not ready for review. Mark the PR as Ready for Review when you're ready for a Cypress team member to review the PR.