[3.12] gh-131818: Add imply `-P` in `-I`'s help message (GH-131819) (#131823)

gh-131818: Add imply `-P` in `-I`'s help message (GH-131819)
(cherry picked from commit 8bd88e2827b2a887c2ea8e5ed0c0575704bfacdf)

Co-authored-by: Hang <bebound@gmail.com>