style: apply dart format to math example and css_bug_fixes_test

Author: vietnguyentuan2019

packages/hyper_render_math/example/example.dart

@@ -25,8 +25,8 @@ class MyApp extends StatelessWidget {
 class MathExamplePage extends StatelessWidget {
   const MathExamplePage({super.key});
 
-  static final _registry =
-      HyperPluginRegistry()..register(const MathNodePlugin());
+  static final _registry = HyperPluginRegistry()
+    ..register(const MathNodePlugin());
 
   static final _document = DocumentNode(children: [
     BlockNode(

test/style/css_bug_fixes_test.dart

@@ -537,6 +537,7 @@ void main() {
           walk(c);
         }
       }
+
       walk(doc);
 
       expect(imgNode, isNotNull);
@@ -562,6 +563,7 @@ void main() {
           walk(c);
         }
       }
+
       walk(doc);
 
       expect(imgNode, isNotNull);
@@ -592,6 +594,7 @@ void main() {
           walk(c);
         }
       }
+
       walk(doc);
 
       expect(linkNode, isNotNull);