[3.10] Docstring: replace pysqlite with sqlite3 (GH-31758) (GH-31777)

Replace two instances of "pysqlite" with "sqlite3" in sqlite3
docstrings. Also reword "is a no-op" to "does nothing" for clarity..
(cherry picked from commit b33a1ae703338e09dc0af5fbfd8ffa01d3ff75da)

Co-authored-by: Erlend Egeberg Aasland <erlend.aasland@innova.no>