fix: include transitive relative imports when loading from local directory (#46022)
* fix: include transitive relative imports when loading from local directory
When loading a custom model from a local folder with trust_remote_code=True,
only direct relative imports of the entry-point file were copied into the
module cache and included in the content hash. Transitive imports (i.e.
imports of imports) were silently skipped, causing ImportError at runtime
for any dependency beyond the first level.
Fix both sites in the local branch to use get_relative_import_files, which
already walks the full transitive closure. Also remove the now-unused
module_file and modules_needed parameters from _compute_local_source_files_hash.
* Update src/transformers/dynamic_module_utils.py
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Co-authored-by: Matt <Rocketknight1@users.noreply.github.com>