On Windows, Python's default encoding is the system locale (e.g., cp1252,
gbk) rather than UTF-8. This causes UnicodeDecodeError when reading
sdkconfig files, CMakeLists.txt, or JSON configs that contain non-ASCII
characters (e.g., Chinese comments, UTF-8 BOM).
Fix: Add explicit encoding='utf-8' to all text file open() calls in:
- scripts/release.py (Path.open() for config.json, CMakeLists.txt, sdkconfig)
- scripts/build_default_assets.py (io.open() for sdkconfig, open() for headers/configs)
- scripts/versions.py (open() for info.json read/write)
Relates to #1792
Co-authored-by: Nicola Spieser <redbasecap@users.noreply.github.com>