fix: Add troubleshooting for Windows filename too long error

Author: sfshaza2

src/content/install/upgrade.md

@@ -167,6 +167,29 @@ the Dart [`pub outdated` documentation]({{site.dart-site}}/tools/pub/cmd/pub-out
 $ flutter pub outdated
 ```
 
+<a id="troubleshooting" aria-hidden="true"></a>
+
+## Troubleshooting
+
+### Windows: "Filename too long" error
+
+When running `flutter upgrade` on Windows, you might encounter an error like:
+
+```text
+error: unable to create file ...: Filename too long
+```
+
+This occurs because the path to a file in the Flutter SDK exceeds the default
+maximum path length limit on Windows.
+
+To resolve this issue, enable long paths support in Git:
+
+```console
+$ git config --system core.longpaths true
+```
+
+If the command fails with a permission error, try running your terminal as an administrator.
+
 [Flutter SDK archive]: /install/archive
 [flutter-announce]: {{site.groups}}/forum/#!forum/flutter-announce
 [pubspec.yaml]: {{site.dart-site}}/tools/pub/pubspec

src/content/release/breaking-changes/index.md

@@ -37,6 +37,8 @@ They're sorted by release and listed in alphabetical order:
 ### Not yet released to stable
 
 * [Merged threads on Linux][]
+* [Stop generating `AssetManifest.json`][]
+* [`$FLUTTER_ROOT/version` replaced by `$FLUTTER_ROOT/bin/cache/flutter.version.json`][]
 * [`FontWeight` also controls the weight attribute of variable fonts][]
 * [Deprecate `containsSemantics` in favor of `isSemantics`][]
 * [Deprecate `findChildIndexCallback` in favor of `findItemIndexCallback` in `ListView` and `SliverList` separated constructors][]
@@ -81,7 +83,6 @@ They're sorted by release and listed in alphabetical order:
 * [Flutter now sets default `abiFilters` in Android builds][]
 * [Merged threads on macOS and Windows][]
 * [The `Visibility` widget is no longer focusable by default when `maintainState` is enabled][]
-* [`$FLUTTER_ROOT/version` replaced by `$FLUTTER_ROOT/bin/cache/flutter.version.json`][]
 
 [Component theme normalization updates]: /release/breaking-changes/component-theme-normalization-updates
 [Deprecate `DropdownButtonFormField` `value` parameter in favor of `initialValue`]: /release/breaking-changes/deprecate-dropdownbuttonformfield-value
@@ -184,15 +185,13 @@ They're sorted by release and listed in alphabetical order:
 [Rename `MemoryAllocations` to `FlutterMemoryAllocations`]: /release/breaking-changes/flutter-memory-allocations
 
 <a id="released-in-flutter-319" aria-hidden="true"></a>
-
 ### Released in Flutter 3.19
 
 * [Deprecated API removed after v3.16][]
 * [Migrate RawKeyEvent/RawKeyboard system to KeyEvent/HardwareKeyboard system][]
 * [Deprecate imperative apply of Flutter's Gradle plugins][]
 * [Default multitouch scrolling][]
 * [Accessibility traversal order of tooltip changed][]
-* [Stop generating `AssetManifest.json`][]
 
 [Deprecated API removed after v3.16]: /release/breaking-changes/3-16-deprecations
 [Migrate RawKeyEvent/RawKeyboard system to KeyEvent/HardwareKeyboard system]: /release/breaking-changes/key-event-migration