Fixes flutter_svg latest version requiring a non null clipBehavior field. (#369)

* Fix nullable type in SvgPicture.asset clipBehavior

SvgPicture.asset expects a non null type for clipBehavior.  This creates a default value that matches SvgPicture default clipBehavior.

* Remove depreciation annotation from clipBehavior

This is to match the latest version of flutter_svg.
See:
https://github.com/dnfield/flutter_svg/blame/master/lib/svg.dart#L181

* Update test resources to match flutter_svg

---------

Co-authored-by: Daichi Furiya <[email protected]>

Author: jetpeter

packages/core/example/lib/gen/assets.gen.dart

@@ -38,9 +38,9 @@ class SvgIntegration extends Integration {
     bool excludeFromSemantics = false,
     SvgTheme theme = const SvgTheme(),
     ColorFilter? colorFilter,
+    Clip clipBehavior = Clip.hardEdge,
     @deprecated Color? color,
     @deprecated BlendMode colorBlendMode = BlendMode.srcIn,
-    @deprecated Clip? clipBehavior,
     @deprecated bool cacheColorFilter = false,
   }) {
     return SvgPicture.asset(