refactor: return 204 No Content from UserTimezoneController update method

[tusharnain]

Summary

This PR refactors the UserTimezoneController::update method to return an explicit 204 No Content response instead of relying on Laravel's default void response behavior.

Changes Made

• Updated the return type from void to Illuminate\Http\Response
• Returned response()->noContent() after successfully updating the session timezone

Rationale

• Makes the controller method more RESTful and semantically correct
• Improves clarity for frontend consumers who now receive a proper 204 response
• Enhances code readability and static analysis support through explicit return type

Impact

There is no change in functionality, but the API behavior is now more explicit. This is a safe and non-breaking change.

Testing

Manually tested via the front-end call and verified that:

• The timezone is still stored in the session as expected
• The HTTP response status is 204 No Content

[Copilot]

Pull Request Overview

This PR refactors the UserTimezoneController update method to explicitly return a 204 No Content response, thereby enhancing RESTful behavior and code clarity.

• Changes the method signature return type from void to Illuminate\Http\Response.
• Adds a return statement using response()->noContent() to provide an explicit 204 response.