fix: respondNoContent() returns Kint script in development mode

[anggadarkprince]

Description
Fixes #7346 about API\ResponseTrait::respondNoContent() returns Kint script in development mode.

Checklist:

• Securely signed commits
• Component(s) with PHPDoc blocks, only if necessary or adds value
• Unit testing, with >80% coverage
• User guide updated
• Conforms to style guide

[kenjis]

Thank you.

You need GPG sign all your commits.
See https://github.com/codeigniter4/CodeIgniter4/blob/develop/contributing/pull_request.md#signing

Can you write test code to prove the bug fix?
https://github.com/codeigniter4/CodeIgniter4/blob/develop/contributing/pull_request.md#unit-testing

[kenjis]

We do not use git merge. Please use git rebase to update your PR branch.
See https://github.com/codeigniter4/CodeIgniter4/blob/develop/contributing/workflow.md#updating-your-branch

And please sign all your commits.
See https://github.com/codeigniter4/CodeIgniter4/blob/develop/contributing/workflow.md#gpg-signing-old-commits

[anggadarkprince]

is it correct now?

[kenjis]

Good! Thank you.

[anggadarkprince]

I add content type checking on unit test, to make sure it returns non-HTML format,

public function testNoContent()
{
    $controller = $this->makeController();

    $this->invoke($controller, 'respondNoContent', ['']);

    $this->assertStringStartsWith('application/json', $this->response->getHeaderLine('Content-Type'));
    $this->assertSame('No Content', $this->response->getReason());
    $this->assertSame(204, $this->response->getStatusCode());
}

because in Toolbar.php it checks the type

// Non-HTML formats should not include the debugbar
// then we send headers saying where to find the debug data
 // for this response
 if ($request->isAJAX() || strpos($format, 'html') === false) {
    $response->setHeader('Debugbar-Time', "{$time}")
         ->setHeader('Debugbar-Link', site_url("?debugbar_time={$time}"));

    return;
}

[MGatner]

Thank you!