onnxruntime

f490d892 - Fix OOB pointer in TensorAt for sub-byte packed types (#28973)

Fix OOB pointer in TensorAt for sub-byte packed types (#28973) ### Description <!-- Describe your changes. --> Reject sub-byte packed types with appropriate error message. The TensorAt API returns a void*, it fundamentally cannot point to a sub-byte element. The fix is to reject sub-byte types at the API boundary, similar to how strings are rejected. Tests have been updated to reflect the changes. ### Motivation and Context <!-- - Why is this change required? What problem does it solve? - If it fixes an open issue, please link to the issue here. --> TensorAt computed pointer offsets using logical element indices but Size() returns the byte size of the packed storage unit (1 byte for Int4x2/UInt4x2 which holds 2 elements). This caused out-of-bounds pointer returns when element indices exceeded the actual buffer size. The API fundamentally cannot return a pointer to a sub-byte element, so reject sub-byte packed types with an appropriate error message, similar to how strings are already rejected. --------- Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>