Remove unused "swiftshader-gl" tag

This is a follow-up of the chromium side cleanup here:
https://chromium-review.googlesource.com/c/chromium/src/+/3799192

Bug: chromium:1099959
Change-Id: I6cd442d8512afe6b845c1f1e6d06406ed27d61db
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/98261
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
diff --git a/webgpu-cts/expectations.txt b/webgpu-cts/expectations.txt
index 2fa38da..38c1f0b 100644
--- a/webgpu-cts/expectations.txt
+++ b/webgpu-cts/expectations.txt
@@ -44,8 +44,6 @@
 #         skia-renderer-disabled
 #         skia-renderer-gl
 #         skia-renderer-vulkan ]
-# SwiftShader
-# tags: [ swiftshader-gl no-swiftshader-gl ]
 # Driver
 # tags: [ mesa_lt_19.1 ]
 # ASan