onnxruntime

Make logic in InsertCastTransformer around forcing a node to fp32 more precise. (#8018)

* Address #7981

Reworked the logic around forcing a node to run on fp32 even if it was supported on fp16.

The github issue had multiple factors. In ORT 1.8 we remove Identity nodes that produce graph outputs as they're not needed. That resulted in a Loop node no longer having output nodes (it produces graph outputs instead), which meant the check in IsSingleInputNodeFloat16Node returned true as there was no longer a downstream Identity node processing fp16 data.

We shouldn't only force a node to fp32 in very specific circumstances, and the changes hopefully check for those more precisely.