Memory leak in sqlite3.Connection.load_extension()

Bug report

Bug description:

Public issue regarding the issue found by @sushi-gif. Here is a summary of the discussion:
The function sqlite3.Connection.load_extension() has a minor memory leak that occurs when SQLite throws an error while loading an extension (sqlite3_load_extension). According to SQLite specifications, the buffer of the error message must be freed manually after use. The attached PR fixes the issue.

Reproduction code:

import sqlite3

cx = sqlite3.connect(":memory:")
cx.enable_load_extension(True)

for _ in range(1000000):
    try:
        cx.load_extension("does_not_exist")
    except sqlite3.Error:
        pass

CPython versions tested on:

CPython main branch

Operating systems tested on:

Linux

Linked PRs

• gh-154110

Commencez par l’implémentation de sqlite3.Connection.load_extension() et suivez son appel à sqlite3_load_extension. Utilisez la reproduction fournie de chargements échoués répétés pour examiner le chemin d’erreur, et vérifiez que la fuite mémoire signalée est corrigée sans modifier le comportement de chargement réussi des extensions.