misc/valentina: fix build on powerpc64*
long double is 64-bit on powerpc64*:
ERROR: [1m/wrkdirs/usr/ports/misc/valentina/work/valentina-54b3c6a47d7c81df864fae531396f19955ab1e22/src/libs/vgeometry/vcubicbezierpath.cpp:315:30: [0m[0;1;31merror: [0m[1mimplicit conversion from 'vsizetype' (aka 'long long') to 'long double' may lose precision [-Werror,-Wimplicit-int-float-conversion][0m
315 | return qFloor(qAbs((size - 4) / 3.0L + 1));[0m
| [0;1;32m ~~~~~^~~ ~[0m1 error generated.