Log Message:
py-pillow_heif: update to 0.21.0.

## [0.21.0 - 2024-11-29]

### Added

- Allow specifying encoder parameters for non-primary images in image sequence. #313

### Changed

- Libheif updated from `1.18.2` to `1.19.5` version. #312
- For macOS(`x86_64`), the minimum supported version for binary wheels has been \ 
raised from `12` to `13`.

### Fixed

- Error `argument '-Ofast' is deprecated` when building from source. #305