Disable flaky golden file test (flutter#144351)

Filed flutter#144350 for follow up.
This test has become flaky and is breaking the tree.

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examples/api/test/widgets/text_magnifier/text_magnifier.0_test.dart

@@ -94,7 +94,10 @@ void main() {
       find.byType(example.TextMagnifierExampleApp),
       matchesGoldenFile('text_magnifier.0_test.png'),
     );
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS, TargetPlatform.android }));
+  },
+    variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS, TargetPlatform.android }),
+    skip: true, // This image is flaky. https://github.com/flutter/flutter/issues/144350
+  );
 
 
   testWidgets('should show custom magnifier in RTL', (WidgetTester tester) async {