• Added new 8-bit float types following IEEE 754 convention:
  ml_dtypes.float8_e4m3, ml_dtypes.float8_e3m4
• Added the 8-bit floating point type ml_dtypes.float8_e8m0fnu, which is the
  OpenCompute MX scale format.
• Added new 4-bit and 6-bit float types:
  ml_dtypes.float4_e2m1fn, ml_dtypes.float6_e2m3fn and ml_dtypes.float6_e3m2fn.
• Fix outputs of float divmod and floor_divide when denominator is zero.