test: skip flaky test for all runs

Author: DifferentialOrange

test/tarantool/cpu_metrics_test.lua

@@ -14,6 +14,8 @@ end)
 
 g.test_cpu = function(cg)
     cg.server:exec(function()
+        t.skip('Flaky test, see https://github.com/tarantool/metrics/issues/492')
+
         local metrics = require('metrics')
         local cpu = require('metrics.tarantool.cpu')
         local utils = require('test.utils') -- luacheck: ignore 431
@@ -26,7 +28,6 @@ g.test_cpu = function(cg)
         t.assert(user_time_metric)
         t.assert(system_time_metric)
         t.assert(user_time_metric[1].value > 0)
-        t.xfail_if(not (system_time_metric[1].value > 0), 'Flaky test')
         t.assert(system_time_metric[1].value > 0)
     end)
 end