[3.13] gh-123968: Fix lower bound for `python -m random --float` (GH-123971) (#124009)

gh-123968: Fix lower bound for `python -m random --float` (GH-123971)
(cherry picked from commit a362c41bc934fabe6bfef9be1962005b38396860)

Co-authored-by: Anders Kaseorg <andersk@mit.edu>