Temporarily stop running tests on D3D12 with use_tint_generator

A Dawn CL landed at the same time as a Tint roll in Dawn, causing
failures in a large number of D3D12 use_tint_generator. Disable testing
of that configuration entirely while we investigate the issue and fix
it.

Bug: dawn:758
Change-Id: I6c897efc637821a20281c91668889ae95c1c2b1a
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/47774
Auto-Submit: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Brandon Jones <bajones@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
diff --git a/src/tests/DawnTest.cpp b/src/tests/DawnTest.cpp
index 26bc121..f35687e 100644
--- a/src/tests/DawnTest.cpp
+++ b/src/tests/DawnTest.cpp
@@ -522,7 +522,6 @@
                 // test skips on all backends, we can remove this and use a test suite with
                 // use_tint_generator in the command line args instead.
                 if (params[i].backendType == wgpu::BackendType::Vulkan ||
-                    params[i].backendType == wgpu::BackendType::D3D12 ||
                     params[i].backendType == wgpu::BackendType::OpenGL ||
                     params[i].backendType == wgpu::BackendType::OpenGLES) {
                     BackendTestConfig configWithTint = params[i];