Stop using InterfaceElementImpl2 (#4041)

This simplifies the code and reduces use of private API.

Author: srawlins

CHANGELOG.md

@@ -1,6 +1,7 @@
 ## 8.3.4-wip
 * The URL for category pages now uses _category name_ instead of
   _category `displayName`_.
+* Require analyzer 7.4.4 APIs.
 
 ## 8.3.3
 

lib/src/model/extension.dart

@@ -5,10 +5,6 @@
 import 'package:analyzer/dart/element/element2.dart';
 import 'package:analyzer/dart/element/nullability_suffix.dart';
 import 'package:analyzer/dart/element/type.dart';
-// ignore: implementation_imports
-import 'package:analyzer/src/dart/element/element.dart';
-// ignore: implementation_imports
-import 'package:analyzer/src/dart/element/type_system.dart';
 import 'package:dartdoc/src/element_type.dart';
 import 'package:dartdoc/src/model/comment_referable.dart';
 import 'package:dartdoc/src/model/kind.dart';
@@ -52,9 +48,8 @@ class Extension extends Container {
     extendedType = library.element.typeSystem.promoteToNonNull(extendedType);
     var otherType = container.modelType.type;
     if (otherType is InterfaceType) {
-      otherType = (library.element.typeSystem as TypeSystemImpl)
-          .instantiateInterfaceToBounds2(
-        element: otherType.element3 as InterfaceElementImpl2,
+      otherType = library.element.typeSystem.instantiateInterfaceToBounds2(
+        element: otherType.element3,
         nullabilitySuffix: NullabilitySuffix.none,
       );
 

pubspec.yaml

@@ -7,7 +7,7 @@ environment:
   sdk: ^3.6.0
 
 dependencies:
-  analyzer: ^7.3.0
+  analyzer: ^7.4.4
   args: ^2.4.1
   collection: ^1.17.0
   crypto: ^3.0.3