[DAR-5293][External] Removed {item_path}/{item_name} validation on push

[JBWilkie]

Problem

This validation logic introduced in DAR-3846 only covers a very rare edge case, and makes very expensive API calls for every push operation

Solution

We remove this validation and may re-introduce this validation on the backend in the future

Changelog

Removed expensive pre-push validation from darwin-py that provided a negligible benefit

[linear]

DAR-5293 Add filtering when skipping remote file paths on `push`