Fix incorrect file permissions in wheel packages (#14930)
Fixes #14920
## Summary
Problem: When building wheel packages, metadata files (such as RECORD,
METADATA, WHEEL, and
license files) were being created with incorrect Unix permissions
(--w--wx---), lacking
read permissions and having unexpected executable permissions.
Solution: The fix ensures that all metadata files in wheel packages are
created with proper
644 (rw-r--r--) permissions by:
- Adding explicit unix_permissions(0o644) setting in the write_bytes
method for metadata
files
- Updating permission constants to use octal notation for clarity
- Improving code comments to document the permission settings
Impact: This change ensures wheel packages created by uv have standard
file permissions
consistent with other Python build tools like setuptools, improving
compatibility and
following Python packaging best practices.