[PAINTROID-797] Update to Flutter 3.41.0

[this-is-varunxyz]

Jira Link - link
New Features and Enhancements

Upgraded the Flutter engine to 3.41.0 and Dart SDK bounds to ^3.11.0 (updated .fvmrc, pubspec.yaml, and .github/workflows/main.yml).

Upgraded the Android build environment to support modern plugins: updated Gradle wrapper to 8.9, Kotlin to 1.9.24, and compileSdk to 36.

Bumped the intl package dependency to ^0.20.2 to satisfy the new framework requirements.

Refactorings and Bug Fixes

Resolved Matrix4 deprecation warnings in drawing_canvas.dart and hand_tool_test.dart by migrating .translate() and .scale() to .translateByDouble() and .scaleByDouble() with explicit 4-dimensional coordinates.

Silenced unavoidable third-party/generated code warnings (experimental floor @TypeConverters and Mockito must_be_immutable) via // ignore comments to ensure the strict make lint CI check passes successfully.

Checklist
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[ ] Add new information to the [Wiki](https://github.com/Catrobat/Paintroid-Flutter/wiki) (Not applicable for framework upgrades)