tests: skip thrd test for now

This test fails sporadically on my platforms and block SDK pre-release.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>

Author: nashif

tests/lib/c_lib/thrd/testcase.yaml

@@ -13,6 +13,7 @@ common:
   arch_exclude:
     # see #89839
     - rx
+  skip: true
 tests:
   libraries.libc.c11_threads.minimal:
     tags: minimal_libc