Those overloads have been documented as obsolete, but never been deprecated.
Add the deprecation macros to trigger warnings as of Qt 6.2.
The overloads taking a single StandardButton should not be deprecated until
Qt 7, as otherwise porting from old to new API will require an unnecessary
cast to StandardButtons for calls with only a single enum value.
The unit test explicitly tests the deprecated members, so disable warnings
there.
Fixes: QTBUG-92483
Change-Id: I283ddce4681eafda2378607f999946e56bbb777e
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>
83eca9a087