feat(ferry_generator): support analyzer ^7.0.0 (#635)

Author: knaeckeKami

packages/ferry_generator/pubspec.yaml

@@ -26,7 +26,7 @@ dependencies:
   glob: ^2.0.1
   built_value_generator: ^8.1.1
   built_value: ^8.1.2
-  analyzer: ">=4.2.0 <7.3.0"
+  analyzer: ">=4.2.0 <8.0.0"
 dev_dependencies:
   test: ^1.16.8
   build_runner: ^2.0.2