x11/xsnow: update to 3.7.5 release (+)

version 3.7.5:
01: data/xsnow.desktop.in: add 'Simulation' to categories
02: main.c: make 'settings->lift snow on bottom',

-offsets working
it appears that xdo_search uses the name argument as
a regular expression, so use ^pcmanfm$ and ^Desktop$.

Changelog: https://www.ratrabbit.nl/ratrabbit/xsnow/changelog/index.html