Add ignoreCheckUploadedFile option to File validator (Fixes #16710)

[t-sakaguchi77]

Hello!

• Type: new feature | bug fix
• Link to issue: Implement option for ignoring is_uploaded_file check in File validator #16710

In raising this pull request, I confirm the following:

• I have read and understood the Contributing Guidelines
• I have checked that another pull request for this purpose does not exist
• I wrote some tests for this PR
• I have updated the relevant CHANGELOG
• I have created a PR for the documentation about this change

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Small description of change:

This PR implements the ignoreCheckUploadedFile option in the File validator, allowing
developers to bypass the internal is_uploaded_file() check. This option is particularly
useful when mocking uploaded files in unit tests.

Additionally, when ignoreCheckUploadedFile is set to true, empty upload arrays
(e.g. []) are now treated as valid rather than causing a validation failure.

This update improves testability while maintaining backwards compatibility.
A unit test has been added to verify this behavior.

Note: I did not update the CHANGELOG because Phalcon maintainers usually handle it on merge.
If it is preferred that contributors update it, I’m happy to add it.

Thanks