Roll ANGLE from 2b56dc3e9134 to 20cc4a9bc250 (5 revisions)

https://chromium.googlesource.com/angle/angle.git/+log/2b56dc3e9134..20cc4a9bc250

2023-06-29 lexa.knyazev@gmail.com D3D11: Fix non-trivial blits for snorm buffers
2023-06-29 cclao@google.com Vulkan: Improve SyncVk::serverWait
2023-06-29 syoussefi@chromium.org Split context state by locality of get/set effect
2023-06-29 syoussefi@chromium.org Pass dirty bits by value
2023-06-29 lexa.knyazev@gmail.com Vulkan: Fix resolve with multiple targets of different formats

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/angle-dawn-autoroll
Please CC amaiorano@google.com,angle-team+autoroll@google.com on the revert to ensure that a human
is aware of the problem.

To file a bug in ANGLE: https://bugs.chromium.org/p/angleproject/issues/entry
To file a bug in Dawn: https://bugs.chromium.org/p/dawn/issues/entry

To report a problem with the AutoRoller itself, please file a bug:
https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md

Bug: None
Tbr: amaiorano@google.com
Change-Id: I78cd348f41dcd2a7c8a8813e9ded8eeb9964432a
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/139720
Bot-Commit: Dawn Autoroller <dawn-autoroll@skia-public.iam.gserviceaccount.com>
Commit-Queue: Dawn Autoroller <dawn-autoroll@skia-public.iam.gserviceaccount.com>
diff --git a/DEPS b/DEPS
index d395699..df5e8b7 100644
--- a/DEPS
+++ b/DEPS
@@ -137,7 +137,7 @@
   },
 
   'third_party/angle': {
-    'url': '{chromium_git}/angle/angle@2b56dc3e91343d7fdcf00355a9849fb536abab6e',
+    'url': '{chromium_git}/angle/angle@20cc4a9bc250a009a88b3491083a86ca6d85b79b',
     'condition': 'dawn_standalone',
   },