graphics/heimer: Update to 3.6.1

Add workaround patch to prevent building with qt6 on machines with
qt5 and/or qt6 installed. qt6 is still experimental and not used
on this port (yet).
https://github.com/juzzlin/Heimer/pull/223

ChangeLog: https://github.com/juzzlin/Heimer/blob/master/CHANGELOG