Rename 'SelectionChangedCause.scribble' to 'SelectionChangedCause.stylusHandwriting' (#161518)

Rename 'SelectionChangedCause.scribble' to
'SelectionChangedCause.stylusHandwriting'

Fixes #159223

## Pre-launch Checklist

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there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
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above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
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Fixes] where supported.
- [x] All existing and new tests are passing.

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[Tree Hygiene]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md
[test-exempt]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests
[Flutter Style Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md
[Features we expect every widget to implement]:
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[breaking change policy]:
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[Discord]:
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[Data Driven Fixes]:
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https://dart.googlesource.com/external/github.com/flutter/flutter/+/586a59211df425b8a1f9b6be1b02662bf88ddc0b
diff --git a/DEPS b/DEPS
index f40fcbd..77c3065 100644
--- a/DEPS
+++ b/DEPS
@@ -239,7 +239,7 @@
 deps = {
   'flutter/engine/src/flutter/third_party/dart': Var('dart_git') + '/sdk' + '@' + 'e2477add3e2c05441d208efca0d4eebab749f471',
 
-  'flutter': Var('flutter_git') + '/mirrors/flutter' + '@' + 'fdd7ebc59ffc53643a428e3770822cba3fee503b',
+  'flutter': Var('flutter_git') + '/mirrors/flutter' + '@' + '586a59211df425b8a1f9b6be1b02662bf88ddc0b',
 
   'flutter/engine/src/flutter/third_party/depot_tools':
   Var('chromium_git') + '/chromium/tools/depot_tools.git' + '@' + '580b4ff3f5cd0dcaa2eacda28cefe0f45320e8f7',
diff --git a/commits.json b/commits.json
index eab152e..ca158f5 100644
--- a/commits.json
+++ b/commits.json
@@ -1,4 +1,4 @@
 {
-  "flutter":"fdd7ebc59ffc53643a428e3770822cba3fee503b",
+  "flutter":"586a59211df425b8a1f9b6be1b02662bf88ddc0b",
   "flutter/engine/src/flutter/third_party/dart":"e2477add3e2c05441d208efca0d4eebab749f471"
 }
\ No newline at end of file