[DirectX] remove getAllocatedType in DXILDataScalarization (#179067)
Update dynamicallyLoadArray to take the allocated type as a parameter
instead of querying getAllocatedType. This is to facilitate removing
other incorrect uses of getAllocatedType, and eventually possibly even
getAllocatedType itself.
Co-authored-by: Claude Sonnet 4.5 <noreply@anthropic.com>