Fix lint cli help (#41783)

<!--
Thanks for opening a PR! Your contribution is much appreciated.
To make sure your PR is handled as smoothly as possible we request that
you follow the checklist sections below.
Choose the right checklist for the change that you're making:
-->

## Bug

- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Errors have a helpful link attached, see `contributing.md`

## Feature

- [ ] Implements an existing feature request or RFC. Make sure the
feature request has been accepted for implementation before opening a
PR.
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [ ] Errors have a helpful link attached, see `contributing.md`

## Documentation / Examples

- [ ] Make sure the linting passes by running `pnpm lint`
- [ ] The "examples guidelines" are followed from [our contributing
doc](https://github.com/vercel/next.js/blob/canary/contributing/examples/adding-examples.md)

Co-authored-by: JJ Kasper <jj@jjsweb.site>

packages/next/cli/next-lint.ts

@@ -116,7 +116,7 @@ const nextLint: cliCommand = async (argv) => {
           -d, --dir Array                Include directory, or directories, to run ESLint - default: 'pages', 'components', and 'lib'
           --file Array                   Include file, or files, to run ESLint
           -c, --config path::String      Use this configuration file, overriding all other config options
-          --ext [String]                 Specify JavaScript file extensions - default: .js, .jsx, .ts, .tsx
+          --ext [String]                 Specify JavaScript file extensions - default: .js, .mjs, .cjs, .jsx, .ts, .mts, .cts, .tsx
           --resolve-plugins-relative-to path::String  A folder where plugins should be resolved from, CWD by default
 
         Initial setup: