bpo-44639: fix typo in sqlite.rst (transation => transaction) (GH-27145)

To my understanding, this is supposed to say "transaction".

See the relevant source:

https://github.com/python/cpython/blob/a158b20019b50e3ece6e4743ec4e6ae8d818b690/Modules/_sqlite/connection.c#L1434-L1467