Allow package.json to be located in subdirectories by processing paths

[MaxiGalaxi]

Description

Enable the NpmProvider to locate and process package.json files that are not in the root directory by correctly handling and resolving paths from the project root.

Possible Solution

npm_provider.py:

@property
def package_file(self) -> Path:
    package_path = next(
        (Path(p) for p in self.config.settings["version_files"] if p.endswith("package.json")),
        None
    )
    if package_path is None:
        raise FileNotFoundError("No package.json found in version_files")
    return package_path

Additional context

No response

Additional context

No response