[Schema Registry Avro] Prepare release (Azure#21215)

Author: deyaaeldeen

sdk/schemaregistry/schema-registry-avro/CHANGELOG.md

@@ -1,6 +1,6 @@
 # Release History
 
-## 1.0.0-beta.8 (Unreleased)
+## 1.0.0-beta.8 (2022-04-05)
 
 ### Features Added
 - A new error type, `AvroError`, is added and is thrown in all error cases except for service calls.
@@ -12,10 +12,6 @@
 - `MessageContent`'s `body` has been renamed to `data`.
 - `MessageAdapter`'s `consumeMessage` and `produceMessage` have been renamed to `consume` and `produce`.
 
-### Bugs Fixed
-
-### Other Changes
-
 ## 1.0.0-beta.7 (2022-03-10)
 
 ### Breaking Changes