Roll vulkan-deps from f730434aca70 to 20ef3c4c476b (2 revisions)

https://chromium.googlesource.com/vulkan-deps.git/+log/f730434aca70..20ef3c4c476b

Changed dependencies:
* vulkan-loader: 477fb9e188..1f92bbb656
* vulkan-validation-layers: 2c8e194e9a..da369877f9

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

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: bajones@google.com
Change-Id: Iaf2896c4253a3336d473db698966db8fdd873f6e
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/94526
Bot-Commit: Dawn Autoroller <dawn-autoroll@skia-public.iam.gserviceaccount.com>
Commit-Queue: Dawn Autoroller <dawn-autoroll@skia-public.iam.gserviceaccount.com>

DEPS

@@ -139,7 +139,7 @@ deps = {
   },
 
   'third_party/vulkan-deps': {
-    'url': '{chromium_git}/vulkan-deps@f730434aca70f8dc2900cd201c235cf39f9509aa',
+    'url': '{chromium_git}/vulkan-deps@20ef3c4c476b54979cb71f9d067acb3835749998',
     'condition': 'dawn_standalone',
   },