Try (and thus prefer) sip >=5 first

If one has sip 4.x and sip 6.x installed sip 4 is picked up ("Found SIP version: 4.19.24") just because it is searched first.

This matters not only because it is nice to use the "latest and greatest", but also because software using the latest PyQt5 (including krita) can't be built with sip 4 at the moment and the maintainer is apparently in no hurry to fix it [1].

[1] https://www.riverbankcomputing.com/pipermail/pyqt/2021-November/044345.html