[lldb][test] Mark sys_info zdump test unsupported on 32 bit Arm Linux

Until #103056 lands
or another more appropriate check can be found.

This test fails on Ubuntu Focal where zdump is built with 32 bit time_t
but passes on Ubuntu Jammy where zdump is built with 64 bit time_t.

Marking it unsupported means Linaro can upgrade its bots to Ubuntu
Jammy without getting an unexpected pass.

Author: DavidSpickett

libcxx/test/std/time/time.zone/time.zone.timezone/time.zone.members/sys_info.zdump.pass.cpp

@@ -14,7 +14,7 @@
 // XFAIL: availability-tzdb-missing
 
 // TODO TZDB Investigate
-// XFAIL: target={{armv(7|8)l-linux-gnueabihf}}
+// UNSUPPORTED: target={{armv(7|8)l-linux-gnueabihf}}
 
 #include <chrono>
 #include <format>