feat: omit_obvious_local_variable_types, specify_nonobvious_local_variable_types

https://github.com/dart-lang/linter/issues/3480

Author: mockturtl

CHANGELOG.md

@@ -3,6 +3,8 @@
 **Prerelease**
 
 - `use_truncating_division` [dart-lang/linter#3930][]
+- OPT-IN: `omit_obvious_local_variable_types` [dart-lang/linter#3480][]
+- OPT-IN: `specify_nonobvious_local_variable_types` [dart-lang/linter#3480][]
 
 ## [3.6.0-0][3.6.0]
 
@@ -206,6 +208,7 @@ No changes.
 [dart-lang/linter#3414]: https://github.com/dart-lang/linter/pull/3414
 [dart-lang/linter#3431]: https://github.com/dart-lang/linter/pull/3431
 [dart-lang/linter#3468]: https://github.com/dart-lang/linter/pull/3468
+[dart-lang/linter#3480]: https://github.com/dart-lang/linter/issues/3480
 [dart-lang/linter#3497]: https://github.com/dart-lang/linter/pull/3497
 [dart-lang/linter#3513]: https://github.com/dart-lang/linter/pull/3513
 [dart-lang/linter#3578]: https://github.com/dart-lang/linter/pull/3578

lib/analysis_options.3.6.0.yaml

@@ -111,6 +111,7 @@ linter:
     - null_check_on_nullable_type_parameter
     - null_closures
     - omit_local_variable_types
+    #    - omit_obvious_local_variable_types  # subset of omit_local_variable_types
     - one_member_abstracts
     - only_throw_errors
     - overridden_fields
@@ -169,6 +170,7 @@ linter:
     #    - sort_constructors_first  # conflicts with auto-sorting all members, per [Fuschia style guide](https://fuchsia.dev/fuchsia-src/development/languages/dart/style#do_order_members_using_the_dart_analyzer)
     #    - sort_pub_dependencies  # conflicts with grouping local packages separately.  Do keep groups sorted.
     - sort_unnamed_constructors_first
+    #    - specify_nonobvious_local_variable_types  # conflicts: omit_local_variable_types
     - test_types_in_equals
     - throw_in_finally
     - tighten_type_of_initializing_formals