Roll Skia from c5a8c4547f59 to 156542f8bf13 (4 revisions) (flutter/engine#42641)

https://skia.googlesource.com/skia.git/+log/c5a8c4547f59..156542f8bf13

2023-06-07 robertphillips@google.com Disable rotated nearest-neighbor testing in the big image test
2023-06-07 johnstiles@google.com Emit simpler WGSL for-loops when the loop-count is known.
2023-06-07 johnstiles@google.com Add WGSL support for the discard statement.
2023-06-07 johnstiles@google.com Allow assignment to function parameters in WGSL.

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 borenet@google.com,brianosman@google.com,jacksongardner@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

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': 'c5a8c4547f5933603c9cf44522152665e4a183ab',
+  'skia_revision': '156542f8bf1341a3b9faa59feb8527a2a7c09b82',
 
   # WARNING: DO NOT EDIT canvaskit_cipd_instance MANUALLY
   # See `lib/web_ui/README.md` for how to roll CanvasKit to a new version.

engine/src/flutter/ci/licenses_golden/licenses_skia

@@ -1,4 +1,4 @@
-Signature: c874fd6732c2486c4c6ff3bd46b18fd9
+Signature: 63743332d310f9ecf23aeb29fcc28764
 
 ====================================================================================================
 LIBRARY: etc1