v2.0.0b2

Second beta of 2.0.0, with fixes from a final review before the release. Please test it,
especially if you rely on seeds, call inpaint from several threads or use
global_mask, and report problems before 2.0.0.

pip install --pre PyPatchMatch==2.0.0b2

Changes that affect results

• Results for a given seed differ from 2.0.0b1 and 1.x. The randomized search uses a
  per-thread std::mt19937 instead of rand(), so concurrent calls from several
  threads are reproducible and the random sequence no longer depends on the platform's
  C runtime. The quality of the results is unchanged.
• Pixels under global_mask keep their input values; they came out black before.
  They are still neither filled nor used as a source.

Fixes

• patch_size < 1 and an empty ijmap raise ValueError instead of crashing or
  hanging.
• Fixed a data race when several threads start their first inpainting at the same time.
• C++: the nearest-neighbor field checks target coordinates against the target size.
  This only matters when the classes are used directly, not for Inpainting.

Packaging

• The wheels include the licenses of the bundled OpenCV code in
  .dist-info/licenses/opencv.
• The arm64 wheels no longer contain OpenCV's Carotene and KleidiCV libraries and are
  smaller (Linux aarch64: 3.1 MB → 2.0 MB, macOS arm64: 2.8 MB → 1.6 MB).
• The README lists the supported platforms and documents all public functions,
  including global_mask.