Update changelog.

Author: twstokes

CHANGELOG.md

@@ -48,6 +48,16 @@ _None._
 
 _None._
 
+## 17.3.0
+
+### New Features
+- Add upgradeURL to JetpackAssistantFeatureDetails
+- Add support for sending magic links to inexistent accounts
+
+### Internal Changes
+- Bump rexml from 3.2.6 to 3.3.9
+- [Tooling] SwiftLint: Use `linter` agent instead of `default` agent
+
 ## 17.2.0
 
 ### New Features