Bug: isRedirect does not respond depending on how redirects are set up.

[lf-uraku-yuki]

Describe the bug
HTTP Testing ->isRedirect() returns true for RedirectReseponse returned by
return redirect()->to(url)
but false for Response returned by
return $this->response->redirect(url, method, status_code)
Returns.

If this is the intended specification, there is no problem, but it is a little difficult to understand.

CodeIgniter 4 version
4.0.4

Affected module(s)
CodeIgniter\Test\FeatureResponse

Expected behavior, and steps to reproduce if appropriate
The controller returns a Response that has executed the method redirect.

Context

• OS: Windows 10 Pro 2004 64bit
• Web server: php spark serve
• PHP version: 7.4.10 Thread Safe 64bit