[3.12] gh-119189: Fix the power operator for Fraction (GH-119242) (GH-119835)

When using the ** operator or pow() with Fraction as the base
and an exponent that is not rational, a float, or a complex, the
fraction is no longer converted to a float.
(cherry picked from commit b9965ef282d6662145d2e05b080c811132ce6fde)

Co-authored-by: Joshua Herman <30265+zitterbewegung@users.noreply.github.com>