b7598

chat: make tool description and parameters optional per OpenAI spec (#18478)

• chat: make tool description and parameters optional per OpenAI spec

Per the OpenAI API specification, both 'description' and 'parameters' fields in tool function definitions are optional. Previously, the parser would throw an exception if these fields were missing.

Attempts to fix #17667

• refactor: use value() for cleaner optional field access

macOS/iOS:

• macOS Apple Silicon (arm64)
• macOS Intel (x64)
• iOS XCFramework

Linux:

• Ubuntu x64 (CPU)
• Ubuntu x64 (Vulkan)
• Ubuntu s390x (CPU)

Windows:

• Windows x64 (CPU)
• Windows arm64 (CPU)
• Windows x64 (CUDA 12) - CUDA 12.4 DLLs
• Windows x64 (CUDA 13) - CUDA 13.1 DLLs
• Windows x64 (Vulkan)
• Windows x64 (SYCL)
• Windows x64 (HIP)

openEuler:

• openEuler x86 (310p)
• openEuler x86 (910b)
• openEuler aarch64 (310p)
• openEuler aarch64 (910b)