Autotest: remove network_WiFi_CSA from suite:wifi_matfunc.

As its Tast counterpart, tast.wifi.CSALeaveChannel, was promoted to
stable and it has better verification logic, let's stop running the test
in suite:wifi_matfunc.

For suite:wificell-cq, we shall also remove the test from it after the
Tast test is added to suite:wificell-cq.

BUG=b:173658464,chromium:1152963
TEST=None

Change-Id: I96c65d103212efc41c1e7f872ffa5ce1cf128f91
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/autotest/+/2560353
Tested-by: Shuo-Peng Liao <deanliao@chromium.org>
Reviewed-by: Billy Zhao <billyzhao@chromium.org>
Reviewed-by: Hsin-chen Chuang <chharry@google.com>
diff --git a/server/site_tests/network_WiFi_CSA/control b/server/site_tests/network_WiFi_CSA/control
index 7889c25..4ca1b18 100644
--- a/server/site_tests/network_WiFi_CSA/control
+++ b/server/site_tests/network_WiFi_CSA/control
@@ -6,7 +6,7 @@
 NAME = 'network_WiFi_CSA'
 TIME = 'SHORT'
 TEST_TYPE = 'Server'
-ATTRIBUTES = ('suite:wifi_matfunc, suite:wificell-cq')
+ATTRIBUTES = ('suite:wificell-cq')
 DEPENDENCIES = 'wificell'
 
 DOC = """