Update CHANGELOG.md (#37784)

Author: lzchen

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

@@ -1,18 +1,12 @@
 # Release History
 
-## 1.0.0b31 (Unreleased)
+## 1.0.0b31 (2024-10-08)
 
 ### Features Added
 
 - Allow tracking of whether in a Azure Functions attach scenario
     ([#37717](https://github.com/Azure/azure-sdk-for-python/pull/37717))
 
-### Breaking Changes
-
-### Bugs Fixed
-
-### Other Changes
-
 ## 1.0.0b30 (2024-09-20)
 
 ### Bugs Fixed