Project-specific exclude patterns are now respected by the poly commands

[DavidVujic]

The commands poly check and poly libs will now respect any existing project-specific exclude patterns.

Example use case:
having dev/test code within the brick and when that particular code import things that the actual brick doesn't use. The poly check and the poly libs command would correctly report if the needed dependencies are missing in the projects using it. By setting an exclusion pattern, the commands will now simply ignore checking code that matches the pattern.

note: the recommended way for tests is still to have them at the top level of the repo (when using the loose theme), and not as part of the brick itself.

# example, project-specific exclusion pattern for uv and hatch
[tool.hatch.build.targets.wheel]
exclude = ["**/the_thing_to_exclude/*"]

The exclusion pattern will also be used when building wheels (this is not new, has been there since before).

The idea origins from issue #382 and is now implemented in the CLI version 1.37.0, and (for Poetry users) in the Poetry plugin version 1.44.0.