Prepare DWDS for version 19.0.0 release (#2068)

Author: elliette

dwds/CHANGELOG.md

@@ -1,6 +1,7 @@
-## 19.0.0-dev
+## 19.0.0
 
 - Allow clients to specify the connected app's entrypoint file. - [#2047](https://github.com/dart-lang/webdev/pull/2047)
+- Don't include non-instantiated variables in stack frame data. - [#2061](https://github.com/dart-lang/webdev/pull/2061)
 - Fix `getObject` failure on record class - [2063](https://github.com/dart-lang/webdev/pull/2063)
 
 ## 18.0.2