bsdisks switched unconditionally to QT6

[Michael Butler]

I have KDE5 installed; this pulls in devel/kf5-solid which has a 
dependency on sysutils/bsdisks like so ..

imb@d5540:/usr/ports/devel/kf5-solid> less Makefile
PORTNAME=       solid
DISTVERSION=    ${KDE_FRAMEWORKS_VERSION}
CATEGORIES=     devel kde kde-frameworks
MAINTAINER=     k...@freebsd.org
COMMENT=        KF5 hardware integration and detection

RUN_DEPENDS=    bsdisks:sysutils/bsdisks

USES=           bison cmake compiler:c++11-lib kde:5 qt:5 tar:xz

 [ .. snip .. ]

But after ..

commit 91ee9ec8e0dbfa97b298e6498900938e71762837
Date:   Tue May 21 21:38:37 2024 +0300

    sysutils/bsdisks: Switch to Qt 6

    PR:             279168

 .. I now have to build and maintain *both* versions of QT.

This makes no sense to me. Can this be fixed to build with just the 
installed version?

        Michael