CI: remove llvmpipe cl flake test

Reviewed-by: Daniel Stone <daniels@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7328>
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index fbd27c8..7db3ebc 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1043,7 +1043,7 @@
     LP_NUM_THREADS: 1
     PIGLIT_PROFILES: cl
     PIGLIT_OPTIONS: >
-      -x bswap -x phatk
+      -x bswap -x phatk -x clz-optimizations
   script:
     - install/piglit/run_cl.sh