Replace unsafe reinterpret_cast with C API calls in op_kernel_info.h
Remove reinterpret_cast of OrtKernelInfo* to internal OpKernelInfo* that breaks ABI across DLL boundaries (vtable mismatch between plugin EP and ORT core).
- KernelInfoCache: use Ort::ConstKernelInfo::GetEp() instead of casting to OpKernelInfo* and calling GetExecutionProvider()->GetOrtEp()
- GetAllocator: use C API KernelInfoGetAllocator + IAllocatorImplWrappingOrtAllocator instead of casting to OpKernelInfo*
- Remove #include core/framework/op_kernel_info.h (no longer needed)
- Add #include core/session/allocator_adapters.h for IAllocatorImplWrappingOrtAllocator