Revert "Test suppression for deqp/functional/gles3/sync.html failure"

This reverts commit f0776695.

Reason for revert: Failures should be fixed.

Original change's description:
> Test suppression for  deqp/functional/gles3/sync.html failure
> 
> deqp/functional/gles3/sync.html is failing intermittently on Win.
> Suppress.
> 
> TBR=kbr@chromium.org
> 
> Bug: 1033662
> Change-Id: Ib4721835bb5cbf2d500dbeb1a411548244a89a05
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1966087
> Reviewed-by: Robert Kroeger <rjkroege@chromium.org>
> Reviewed-by: Kenneth Russell <kbr@chromium.org>
> Commit-Queue: Robert Kroeger <rjkroege@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#724414}

TBR=rjkroege@chromium.org,kbr@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 1033662
Change-Id: I211cba88f49165522a5083240476dad4ae5a0d51
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2007109Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: Kenneth Russell <kbr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#732946}

content/test/gpu/gpu_tests/test_expectations/webgl2_conformance_expectations.txt

@@ -108,7 +108,6 @@ crbug.com/792210 [ nvidia ] conformance/glsl/bugs/in-parameter-passed-as-inout-a
 
 # Intel flaky issues
 crbug.com/912579 [ opengl win passthrough intel ] conformance2/rendering/out-of-bounds-index-buffers-after-copying.html [ RetryOnFailure ]
-crbug.com/1033662 [ opengl win passthrough intel ] deqp/functional/gles3/sync.html [ RetryOnFailure ]
 
 # Intel failed issues
 crbug.com/795030 [ opengl win passthrough intel ] deqp/functional/gles3/shadercommonfunction.html [ Failure ]