Add @final to several stdlib classes that cannot be subclassed at runtime (#7213)

stdlib/sqlite3/dbapi2.pyi

@@ -2,6 +2,7 @@ import sys
 from _typeshed import Self, StrOrBytesPath
 from datetime import date, datetime, time
 from typing import Any, Callable, Generator, Iterable, Iterator, Protocol, TypeVar
+from typing_extensions import final
 
 _T = TypeVar("_T")
 
@@ -223,6 +224,7 @@ class OperationalError(DatabaseError): ...
 
 OptimizedUnicode = str
 
+@final
 class PrepareProtocol:
     def __init__(self, *args: Any, **kwargs: Any) -> None: ...