This follows a499d1772d ("build: qt-utils: Use
QML_IMPORT_PATH for Qt 6.").
* guix/build/qt-utils.scm (variables-for-wrapping): Use QML_IMPORT_PATH2 when
the Qt major version is <= 6, QML_IMPORT_PATH otherwise.
Change-Id: I2dd1d426aef117105708cc4004078deaa28c15cd
Signed-off-by: Maxim Cournoyer <maxim.cournoyer@gmail.com>