x11/cde*: Remove call to tzsetall()

As of src d5c85ac6526d, the tzcode update removed the tzsetwall()
function. Our tzcode upstream removed tzsetwall() in their commit
d36f8f5b6983. The reason they did this was that tzsetwall() was
"undocumented and ineffective."

MFH: 2023Q1
(cherry picked from commit 30387c1f04de9965f4fa56b4f95a6676477ebe72)