disable avoid_private_typedef_functions lint (flutter#16495)

Author: a14n

analysis_options.yaml

@@ -64,7 +64,7 @@ linter:
     - avoid_init_to_null
     - avoid_null_checks_in_equality_operators
     # - avoid_positional_boolean_parameters # not yet tested
-    # - avoid_private_typedef_functions # not yet tested
+    # - avoid_private_typedef_functions # we prefer having typedef (discussion in https://github.com/flutter/flutter/pull/16356)
     - avoid_relative_lib_imports
     - avoid_renaming_method_parameters
     - avoid_return_types_on_setters

analysis_options_repo.yaml

@@ -57,7 +57,7 @@ linter:
     - avoid_init_to_null
     - avoid_null_checks_in_equality_operators
     # - avoid_positional_boolean_parameters # not yet tested
-    # - avoid_private_typedef_functions # not yet tested
+    # - avoid_private_typedef_functions # we prefer having typedef (discussion in https://github.com/flutter/flutter/pull/16356)
     - avoid_relative_lib_imports
     - avoid_renaming_method_parameters
     - avoid_return_types_on_setters