[M109] Suppress flaky WebGPU test mapAsync,offsetAndSizeOOB

Test is:
worker_webgpu:api,validation,buffer,mapping:mapAsync,offsetAndSizeOOB

A bugfix for this went into M110, but it's not important enough to merge
the bugfix back to M109 (it was a non-regression, I think).

Bug: chromium:1406687
No-Try: true
Change-Id: I30e7314ef3d29b12687a8ab20d74d4848cd7eac6
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/116960
Auto-Submit: Kai Ninomiya <kainino@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>
Kokoro: Austin Eng <enga@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
diff --git a/webgpu-cts/expectations.txt b/webgpu-cts/expectations.txt
index 9896878..72ce350 100644
--- a/webgpu-cts/expectations.txt
+++ b/webgpu-cts/expectations.txt
@@ -547,6 +547,7 @@
 ################################################################################
 crbug.com/1357206 [ nvidia-0x2184 win10 ] worker_webgpu:api,validation,buffer,mapping:getMappedRange,offsetAndSizeAlignment,mappedAtCreation: [ Failure ]
 crbug.com/1357206 [ nvidia-0x2184 win10 ] worker_webgpu:api,validation,buffer,mapping:mapAsync,offsetAndSizeAlignment: [ Failure ]
+crbug.com/1406687 [ nvidia-0x2184 win10 ] worker_webgpu:api,validation,buffer,mapping:mapAsync,offsetAndSizeOOB: [ Failure ]
 
 ################################################################################
 # Const-eval version of bitwise XOR failing on Windows