Replace float_t with float (#16484)
A couple of places in onnxruntime used `float_t` data type alias as an
alternative to `float`. However, this is not entirely correct, since
`float_t` is an implementation-defined type alias, which may be `float`,
`double`, `long double` or some other implementation-defined data type,
depending on the state of the internal `FLT_EVAL_METHOD` macro:
https://en.cppreference.com/w/c/numeric/math/float_t
On most major platforms and compilers (clang, GCC, MSVC) this is only a
cosmetic change and will not lead to any changes. However, icpx compiler
(and legacy icc) tends to substitute `float_t` with `long double`,
resulting in a linker error (unresolved reference) to the base onnx
library, that only contains the `ParseData` function for `float` and
`double` as in
[here](https://github.com/onnx/onnx/blob/9264e093676f40a48aee819b8013ef285e3d4fc5/onnx/defs/tensor_proto_util.cc#L133-L134).
Overall, this PR cleans up the implementation-defined behaviour and
enables building onnxruntime with icpx.
