Roll Skia from 76898dad9fda to a631fefdba37 (2 revisions) (flutter#45027)

https://skia.googlesource.com/skia.git/+log/76898dad9fda..a631fefdba37

2023-08-23 johnstiles@google.com Disable Graphite SkSL tests on Linux in Release.
2023-08-23 herb@google.com Implement and document intersection

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 brianosman@google.com,jimgraham@google.com,lovisolo@google.com,rmistry@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://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

Author: skia-flutter-autoroll

DEPS

@@ -18,7 +18,7 @@ vars = {
   'llvm_git': 'https://llvm.googlesource.com',
   # OCMock is for testing only so there is no google clone
   'ocmock_git': 'https://github.com/erikdoe/ocmock.git',
-  'skia_revision': '76898dad9fda119aa14b05fba18d32965c54015e',
+  'skia_revision': 'a631fefdba37d8957d5a5c32d63e58e2856e6d4a',
 
   # WARNING: DO NOT EDIT canvaskit_cipd_instance MANUALLY
   # See `lib/web_ui/README.md` for how to roll CanvasKit to a new version.

ci/licenses_golden/licenses_skia

@@ -1,4 +1,4 @@
-Signature: edd1ae502e56b8317e70a6dc5f50f678
+Signature: d586778164cfad70f566ee8eec743578
 
 ====================================================================================================
 LIBRARY: etc1