linter: add missing option for `unicorn/numeric-separators-style` rule

> `unicorn/numeric-separators-style` rule is missing `fractionGroupLength` option for `number` type: https://github.com/sindresorhus/eslint-plugin-unicorn/blob/main/docs/rules/numeric-separators-style.md#options 

 _Originally posted by @baevm in [#22955](https://github.com/oxc-project/oxc/issues/22955#issuecomment-4699229183)_