tint e2e: add skip on test that times out on bots

This test takes longer than 2 minutes to generate and validate on bots,
such as ci/cmake-linux-clang-dbg-x64-asan.

Change-Id: I32a38c8e83ebf82e1c0bc86075d897bb2a51112c
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/210474
Auto-Submit: Antonio Maiorano <amaiorano@google.com>
Reviewed-by: Ryan Harrison <rharrison@chromium.org>
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
diff --git a/test/tint/benchmark/skinned-shadowed-pbr-fragment.wgsl.expected.ir.glsl b/test/tint/benchmark/skinned-shadowed-pbr-fragment.wgsl.expected.ir.glsl
new file mode 100644
index 0000000..708a412
--- /dev/null
+++ b/test/tint/benchmark/skinned-shadowed-pbr-fragment.wgsl.expected.ir.glsl
@@ -0,0 +1,3 @@
+SKIP: FAILED
+
+Times out on bots