[3.14] gh-134215: PyREPL: Do not show underscored modules by default during autocompletion (gh-134267) (gh-134388)

(cherry picked from commit a3a3cf6d157948ed64ae837d6310b933a39a2493)

Co-authored-by: Kevin Hernández <kevin.hernandez@unet.edu.ve>
Co-authored-by: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com>
Co-authored-by: Tomas R. <tomas.roun8@gmail.com>
Co-authored-by: Łukasz Langa <lukasz@langa.pl>