changelog: drop workspace reference from 3.5

Not ready to announce it (yet)

Change-Id: Icc7fbdaa2564511429a1b5601afcce065a5663f5
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/373162
Auto-Submit: Kevin Moore <kevmoo@google.com>
Commit-Queue: Sigurd Meldgaard <sigurdm@google.com>
Reviewed-by: Sigurd Meldgaard <sigurdm@google.com>
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 250656c..03286c3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -75,8 +75,6 @@
 
 #### Pub
 
-- Support for [workspaces](https://dart.dev/go/pub-workspaces). Multiple
-  related packages can be resolved together when developing.
 - New flag `dart pub downgrade --tighten` to restrict lower bounds of
   dependencies' constraints to the minimum that can be resolved.