remove super_goes_last (#27690)

In Dart 2, it is a compile-time error if a superinitializer
appears in an initializer list at any other position than at the end so this
rule is made redundant by the Dart analyzer's basic checks and is no longer
necessary.

analysis_options.yaml

@@ -151,7 +151,7 @@ linter:
     - sort_constructors_first
     - sort_pub_dependencies
     - sort_unnamed_constructors_first
-    - super_goes_last
+    # - super_goes_last # no longer needed w/ Dart 2
     - test_types_in_equals
     - throw_in_finally
     # - type_annotate_public_apis # subset of always_specify_types

packages/flutter/lib/analysis_options_user.yaml

@@ -67,7 +67,7 @@ linter:
     - slash_for_doc_comments
     # - sort_constructors_first
     # - sort_unnamed_constructors_first
-    - super_goes_last
+    # - super_goes_last # no longer needed w/ Dart 2
     - test_types_in_equals
     - throw_in_finally
     # - type_annotate_public_apis # subset of always_specify_types