Remove unused internal macros (#102415)

Since #101826 was merged, the internal macro `_Py_InIntegralTypeRange` is unused, as are its supporting macros `_Py_IntegralTypeMax` and `_Py_IntegralTypeMin`. This PR removes them.

Note that `_Py_InIntegralTypeRange` doesn't actually work as advertised - it's not a safe way to avoid undefined behaviour in an integer to double conversion.