[Sheriff] Disable flaky http/tests/devtools/coverage/gutter-css.js

TBR=sigurds

Bug: 1042689
Change-Id: Ied0c235d3922cd7b355bcdb24b8bb4fbb38d5954
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2003856
Commit-Queue: Jan Wilken Dörrie <jdoerrie@chromium.org>
Reviewed-by: Jan Wilken Dörrie <jdoerrie@chromium.org>
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#732752}

third_party/blink/web_tests/TestExpectations

@@ -6372,3 +6372,5 @@ crbug.com/1042347 external/wpt/html/cross-origin-opener-policy/blob-popup.https.
 crbug.com/1042205 virtual/off-main-thread-css-paint/external/wpt/css/css-paint-api/paint2d-filter.https.html [ Pass Timeout ]
 crbug.com/1042681 external/wpt/html/cross-origin-embedder-policy/blob.https.html [ Pass Failure ]
 crbug.com/1042694 fast/forms/form-control-with-state-eager-tracing-crashTest.html [ Pass Timeout ]
+crbug.com/1042689 [ Linux ] http/tests/devtools/coverage/gutter-css.js [ Pass Timeout ]
+crbug.com/1042689 [ Win ] http/tests/devtools/coverage/gutter-css.js [ Pass Timeout ]