chore(analysis/special_functions/pow): golf a proof (#14093)
chore(analysis/special_functions/pow): golf a proof (#14093)

* move `real.abs_rpow_of_nonneg` up;
* use it to golf a line in `real.abs_rpow_le_abs_rpow`.





leanprover-community/mathlib,leanprover-community/mathlib