[3.12] gh-118221: Always use the default row factory in sqlite3.iterdump() (#118223...

[3.12] gh-118221: Always use the default row factory in sqlite3.iterdump() (#118223) (#118270)

sqlite3.iterdump() depends on the row factory returning resulting rows
as tuples; it will fail with custom row factories like for example a
dict factory.

With this commit, we explicitly reset the row factory of the cursor used
by iterdump(), so we always get predictable results. This does not
affect the row factory of the parent connection.

Co-authored-by: Mariusz Felisiak <felisiak.mariusz@gmail.com>
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>