fix(ls): Allow explicit null value for options parameter

[mitsuki31]

Summary

This pull request addresses a type safety issue related to the options parameter in all ls* functions.

Details

Previously, the options parameter for all ls* functions was defined as non-nullable. This meant you couldn't explicitly pass null as an argument, even though using undefined or an empty object ({}) was a valid way to indicate no options.

This change updates the type definition for the options parameter to allow null as a valid value alongside undefined. This provides more flexibility in how you can use the ls* functions.

Previously if you write code like this:

const dirs = await ls('./foo', null, lsTypes.LS_D);

An error will be thrown from the internal function, with message Uncaught TypeError: Cannot read properties of null (reading 'match'). Now after this change, the issue has been fixed and can the options parameter is now nullable.

Benefits

• Improved type safety:
  The type definition now accurately reflects the acceptable values for the options parameter.
• Enhanced developer experience:
  Developers can now explicitly pass null to indicate no options, leading to clearer code and potentially fewer runtime errors.