ci/zink: Report flake test

Mark 'KHR-GL46.shader_image_load_store.advanced-sso-subroutine' as
flake since it failed several times while attempting to merge this MR.

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15238>

src/gallium/drivers/zink/ci/zink-lvp-flakes.txt

@@ -1,6 +1,7 @@
 dEQP-GLES2.functional.texture.filtering.cube.nearest_linear_mirror_l8_pot
 spec@khr_debug@push-pop-group_gl.*
 glx@glx-multi-window-single-context
+KHR-GL46.shader_image_load_store.advanced-sso-subroutine
 
 # "Pending expose event- rerunning."
 #  exit status: signal: 11"
@@ -9,4 +10,3 @@ glx@glx-copy-sub-buffer samples=2
 # "free(): invalid next size (fast)"
 # since it's heap corruption, it may or may not appear in a particular run
 spec@arb_compute_variable_group_size@local-size
-