Disable system_health.memory_desktop/browse:tech:discourse_infinite_scroll:2018

This test is flaky on Linux bots

TBR=waffles@chromium.org, crouleau@chromium.org

Bug: 1060068
Change-Id: I715072f596a0a7d6ed2cbf3b20b608ba0a2743f9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2095614Reviewed-by: Kyle Milka <kmilka@chromium.org>
Commit-Queue: Kyle Milka <kmilka@chromium.org>
Cr-Commit-Position: refs/heads/master@{#748877}

tools/perf/benchmarks/system_health_smoke_test.py

@@ -88,6 +88,8 @@ _DISABLED_TESTS = frozenset({
     'system_health.memory_desktop/browse:news:hackernews:2018',
     # crbug.com/992436
     'system_health.memory_desktop/browse:social:twitter:2018'
+    # crbug.com/1060068
+    'system_health.memory_desktop/browse:tech:discourse_infinite_scroll:2018',
     # ]
 })