Prepare for the July Identity beta release. (#5770)

* Prepare for the July Identity beta release.

* Update release date.

* Update CL - remove empty headings.

Author: ahsonkhan

sdk/identity/azure-identity/CHANGELOG.md

@@ -1,19 +1,13 @@
 # Release History
 
-## 1.9.0-beta.2 (Unreleased)
+## 1.9.0-beta.2 (2024-07-22)
 
 ### Features Added
 
 - Added `ClientAssertionCredential` to enable applications to authenticate with custom client assertions.
 - Added support for providing a Resource ID to `ManagedIdentityCredential`.
 - Added support for customizing the IMDS endpoint within `ManagedIdentityCredential`.
 
-### Breaking Changes
-
-### Bugs Fixed
-
-### Other Changes
-
 ## 1.9.0-beta.1 (2024-06-21)
 
 ### Features Added