update release date (#36028)

Author: l0lawrence

sdk/eventhub/azure-eventhub/CHANGELOG.md

@@ -1,17 +1,11 @@
 # Release History
 
-## 5.12.1 (Unreleased)
-
-### Features Added
-
-### Breaking Changes
+## 5.12.1 (2024-06-11)
 
 ### Bugs Fixed
 
 - Fixed a bug where the correct URI was not being used for consumer authentication, causing issues when assigning roles at the consumer group level. ([#35337](https://github.com/Azure/azure-sdk-for-python/issues/35337))
 
-### Other Changes
-
 ## 5.12.0 (2024-05-16)
 
 ### Features Added