Update CHANGELOG.md (Azure#39874)

Author: lzchen

sdk/monitor/azure-monitor-opentelemetry-exporter/CHANGELOG.md

@@ -1,6 +1,6 @@
 # Release History
 
-## 1.0.0b34 (Unreleased)
+## 1.0.0b34 (2025-02-26)
 
 ### Features Added
 
@@ -13,12 +13,6 @@
   - Support stable http semantic conventions for standard metrics + synthetic type for server standard metrics
   ([#39799](https://github.com/Azure/azure-sdk-for-python/pull/39799))
 
-### Breaking Changes
-
-### Bugs Fixed
-
-### Other Changes
-
 ## 1.0.0b33 (2025-01-14)
 
 ### Features Added