qt6: Handle different signatures of QANEF::nativeEventFilter

Summary:
This change ensures compatibility across all supported Qt versions.
See https://bugreports.qt.io/browse/QTBUG-72968

This is a backport of core-gui#840

Depends on D18200

Test Plan: hard to test, requires compiling on/for windows. Let's see if it passes on CI

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Subscribers: Fabien

Differential Revision: https://reviews.bitcoinabc.org/D18201