Release v2.26.5

Release: v2.26.5 [skip ci]

Patch

• Fix: Avoid aliasing native BF16 values (e05a071)
• Make: Stabilize release pipelines and adopt NuGet trusted publishing (46a4dcb)
• Fix: Parenthesize splitmix64_t min and max for windows.h (0f1c5f2)
• Make: Add install targets for C library and header (4160e47)
• Make: Support relocatable pkg-config paths with @only substitution (679e190)
• Make: Use GNUInstallDirs variables for install paths (14f9807)
• Fix: Preserve top-k neighbors when cropping Python datasets (88faaf2)
• Fix: Preserve distinct node-level streams across threads and reserves (30d75a4)