Release v2.26.6

Release: v2.26.6 [skip ci]

Patch

• Make: Require kernels that build on GCC 16 and load on macOS 14 (343dc7b)
• Fix: Reject a zero count in Python search (f6d6f84)
• Docs: Define the distances built-in metrics return (3ea3624)
• Make: Install the server image's Python packages in a venv (3a4cb6e)
• Fix: Keep key lookups usable when the rehash cannot allocate (1633e25)
• Fix: Validate nested vector batches in JavaScript bindings (8480ece)
• Fix: Reject out-of-range keys in JavaScript bindings (b65a420)
• Fix: Bound entry slot and max level from the file header (9c25176)
• Fix: Pass executor to exact search in C API (f51074d)
• Improve: Clarify Python worker parallelism (5d3f821)
• Make: Refresh Python wheels and release publishing (21c44e7)
• Fix: Preserve Go filter callbacks across C calls (ad77fe7)