[release] Add 2.17.4 release notes

This is a patch release that fixes:

- Improve analysis of enums and switch (issue [#49188]).
- Fix compiler crash when initializing Finalizable objects (issue [#49075]).

[#49188]: #49188
[#49075]: #49075

Change-Id: If2059474ce2acbadf7f3c6e407f0087d262e2842
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/249161
Reviewed-by: Michael Thomsen <mit@google.com>

CHANGELOG.md

@@ -167,7 +167,7 @@ Updated the Linter to `1.25.0`, which includes changes that
 - fix `unawaited_futures` to handle string interpolated
  futures.
 - update `use_colored_box` to not flag nullable colors,
-- add new lint: 
+- add new lint:
  `unnecessary_null_aware_operator_on_extension_on_nullable`.
 - fix `no_leading_underscores_for_local_identifiers`
  to lint local function declarations.
@@ -192,6 +192,16 @@ Updated the Linter to `1.25.0`, which includes changes that
 * `dart pub outdated` now shows which of your dependencies are discontinued.
 * `dart pub publish` will now list all the files it is about to publish.
 
+## 2.17.4 - 2022-06-20
+
+This is a patch release that fixes:
+
+- Improve analysis of enums and switch (issue [#49188]).
+- Fix compiler crash when initializing Finalizable objects (issue [#49075]).
+
+[#49188]: https://github.com/dart-lang/sdk/issues/49188
+[#49075]: https://github.com/dart-lang/sdk/issues/49075
+
 ## 2.17.3 - 2022-06-01
 
 This is a patch release that fixes: