Increment package version after release of azure-eventgrid (#38612)

sdk/eventgrid/azure-eventgrid/CHANGELOG.md

@@ -1,5 +1,15 @@
 # Release History
 
+## 4.21.1 (Unreleased)
+
+### Features Added
+
+### Breaking Changes
+
+### Bugs Fixed
+
+### Other Changes
+
 ## 4.21.0 (2024-11-19)
 
 ### Features Added

sdk/eventgrid/azure-eventgrid/azure/eventgrid/_version.py

@@ -6,4 +6,4 @@
 # Changes may cause incorrect behavior and will be lost if the code is regenerated.
 # --------------------------------------------------------------------------
 
-VERSION = "4.21.0"
+VERSION = "4.21.1"