tests: Reduce the size of the test suite files
If we were to move to meson, the whole test suite would be available in the dist, so make sure this doesn't balloon the size of the tarball.
Size reduction executed with:
for i in * ; do SIZE=$(stat --printf="%s" $i) ; if [ SIZE -gt 131072 ] ; then dd if=
i of=$i.tmp bs=128k count=1 && mv $i.tmp $i ; fi ; done