[stable] Roll dart_style which fixes formatting ()?.

Fixes: #52591

Bug: dart-lang/dart_style#1224
Change-Id: I5d87c487e036d69cb5e3ed3289f3b066132a8dea
Cherry-pick: https://dart-review.googlesource.com/c/sdk/+/306122
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/306911
Auto-Submit: Bob Nystrom <rnystrom@google.com>
Reviewed-by: William Hesse <whesse@google.com>
Commit-Queue: William Hesse <whesse@google.com>

CHANGELOG.md

@@ -1,3 +1,11 @@
+## 3.0.4
+
+This is a patch release that:
+
+- Handles formatting nullable record types with no fields (dart_style issue [#1224]).
+
+[#1224]: https://github.com/dart-lang/dart_style/issues/1224
+
 ## 3.0.3
 
 This is a patch release that:

DEPS

@@ -133,7 +133,7 @@ vars = {
   #   and land the review.
   #
   # For more details, see https://github.com/dart-lang/sdk/issues/30164.
-  "dart_style_rev": "156f5c8c3bfe4e3b8e7adc95f7cf24d9500f11c6", # disable rev_sdk_deps.dart
+  "dart_style_rev": "3470ab8451567dad237ddd54f992bfed066a2707", # disable rev_sdk_deps.dart
   "dartdoc_rev": "d01ddc58600c0d2edbbd953d2074996c36604cfc",
   "ffi_rev": "04fa38ab45cb2957f9059e03031b53906c2c4385",
   "file_rev": "72a67c33f90bfb7e10057e286e06d2fe3baa4d98",