[flake8-bandit] Make S201 example error out-of-the-box

[MeGaGiGaGon]

Summary

Part of #18972

This PR makes flask-debug-true (S201)'s example error out-of-the-box

Old example

import flask

app = Flask()

app.run(debug=True)

New example

from flask import Flask

app = Flask()

app.run(debug=True)

Imports were also added to the Use instead: section to make it valid code out-of-the-box.

Test Plan

N/A, no functionality/tests affected

[github-actions]

ruff-ecosystem results

Linter (stable)

✅ ecosystem check detected no linter changes.

Linter (preview)

✅ ecosystem check detected no linter changes.

[ntBre]

Thanks!