fix: change animation widget to Widget Function

[juan-campuzano]

Golden animation testing improvements

• Refactored the BcGoldenCapture.animation API to accept a Widget Function() instead of a Widget, enabling more flexible widget instantiation and improving test reliability. This change is reflected in both the implementation and the example tests. [1] [2] [3] [4]
• Added support for device configuration in animation tests by applying config.device to the test window if provided, allowing tests to run with custom device settings.

Golden file output and resource management

• Updated golden file naming conventions for animation tests, removing the _flow suffix and standardizing output names for clarity.
• Changed the animation capture logic to run asynchronously only for the capture step, and simplified the test execution flow for improved stability. [1] [2]
• Commented out result.dispose() calls in the local file comparator to avoid potential resource disposal issues during golden file comparison. [1] [2]

Dependency and configuration updates

• Updated the package version to 2.0.0-alpha.4 and adjusted dependencies in pubspec.yaml for better compatibility, including downgrading flutter_svg, dart_code_linter, mockito, and build_runner. [1] [2]

Minor API and test adjustments

• Modified the usage of textScaleFactor in _AppWidgetBaseTest for more direct control over text scaling in tests.

CI updates

• Add pana score