Roll Skia from 8505be5b584e to 966d9c665eed (2 revisions) (#166675)

https://skia.googlesource.com/skia.git/+log/8505be5b584e..966d9c665eed

2025-04-07 skia-autoroll@skia-public.iam.gserviceaccount.com Roll
vulkan-deps from 3369cb8e1cb9 to fb4fe29989cb (1 revision)
2025-04-07 skia-autoroll@skia-public.iam.gserviceaccount.com Roll Dawn
from db66eb3d2ec7 to fbd6b201958b (16 revisions)

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

To file a bug in Skia: https://bugs.chromium.org/p/skia/issues/entry
To file a bug in Flutter:
https://github.com/flutter/flutter/issues/new/choose

To report a problem with the AutoRoller itself, please file a bug:
https://issues.skia.org/issues/new?component=1389291&template=1850622

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

DEPS

@@ -14,7 +14,7 @@ vars = {
   'flutter_git': 'https://flutter.googlesource.com',
   'skia_git': 'https://skia.googlesource.com',
   'llvm_git': 'https://llvm.googlesource.com',
-  'skia_revision': '8505be5b584e8796ff4b0cdf03a22d29d32e4e60',
+  'skia_revision': '966d9c665eed9b78eeb7c2e591539c5bae141cab',
 
   # WARNING: DO NOT EDIT canvaskit_cipd_instance MANUALLY
   # See `lib/web_ui/README.md` for how to roll CanvasKit to a new version.