fix: Path checking for the existence of a namespaced helper file

[yllumi]

Description
The update in version 4.5.6 caused an error in the logic check line for the path of the namespaced helper file. The return value of $loader->locateFile is a string containing the file path if found, and false if not found. The FileNotFoundException should be executed if $path value is false.

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

[neznaika0]

@kenjis sorry, i missed it in
#9249 . There was a replacement:

- if (empty($path)) {
+ if ($path !== '') {

[samsonasik]

should be strict empty string or false

Suggested change

	if (!$path) {
	if ($path === false || $path === '') {

[samsonasik]

Ok, $path === false should be enough, since empty string should never happen

Suggested change

	if (!$path) {
	if ($path === false) {

[samsonasik]

@yllumi it is recommended to create a branch per PR, you can read guideline for it

https://github.com/codeigniter4/CodeIgniter4/blob/develop/contributing/pull_request.md#how-to-guide

Also, please provide failing test case on tests directory for the patch, thank you.

[samsonasik]

@yllumi I created new PR with include test case for it:

• fix: handle namespaced helper found on Common helper #9354