Disable test to land DevTools Settings discoverability improvements

This small CL disables the elements-tab-stops test in order to land
DevTools Settings discoverability improvements [1].

[1] adds a new Settings button to the top-level toolbar,
which appears as a tab-stop in this test.

[2] fixes the test so that the new tab stop is in the expectations file.

[1] https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2049183
[2] https://chromium-review.googlesource.com/c/chromium/src/+/2118870

Bug: 1050855
Change-Id: I6fd5386f84220f22d00e54255a7bdcfe8b4cb9e3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2117328
Commit-Queue: Brian Cui <brcui@microsoft.com>
Auto-Submit: Brian Cui <brcui@microsoft.com>
Reviewed-by: John Emau <John.Emau@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#753335}

third_party/blink/web_tests/TestExpectations

@@ -6489,6 +6489,10 @@ crbug.com/1048149 [ Mac ] virtual/form-controls-refresh-disabled/fast/forms/cale
 # Upcoming DevTools change
 crbug.com/1006759 http/tests/devtools/profiler/cpu-profiler-save-load.js [ Pass Failure Timeout ]
 crbug.com/1006759 http/tests/devtools/profiler/heap-snapshot-loader.js [ Pass Failure ]
+
+# Temporarily disabled to land changes in DevTools, multiple dependent CLs
+# [1] https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2049183
+# [2] https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2119670
 crbug.com/1064472 http/tests/devtools/elements/elements-tab-stops.js [ Pass Failure ]
 
 # Flaky tests blocking WPT import