Disable fetch-samesite-cookies.js flaky test

The test
http/tests/inspector-protocol/fetch/fetch-samesite-cookies.js
is flaky on both linux and mac.

Bug: 1318952
Change-Id: I388b15430e9dff3e28ab48c1451e389fbbc61d3e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3602647
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Liviu Tinta <liviutinta@chromium.org>
Owners-Override: Liviu Tinta <liviutinta@chromium.org>
Cr-Commit-Position: refs/heads/main@{#995368}

third_party/blink/web_tests/TestExpectations

@@ -7718,6 +7718,7 @@ crbug.com/1288839 virtual/feature-policy-permissions/external/wpt/mediacapture-s
 crbug.com/1318695 http/tests/devtools/elements/highlight/highlight-multiple-css-grid.js [ Failure Pass ]
 crbug.com/1318929 http/tests/devtools/console/console-uncaught-promise.js [ Failure Pass ]
 crbug.com/1282966 http/tests/security/mixedContent/insecure-plugin-in-iframe.html [ Failure Pass ]
+crbug.com/1318952 http/tests/inspector-protocol/fetch/fetch-samesite-cookies.js [ Failure Pass ]
 
 # Imported WPT crashes on desktop platforms
 crbug.com/1318456 [ Linux ] virtual/prerender/external/wpt/speculation-rules/prerender/opt-out.html [ Crash Skip Timeout ]