Updated README to specify support for python versions 3.9+ since support for 3.8 was removed (Azure#42464)

* Updated README to specify support for python versions 3.9+ since support for 3.8 was removed

* Updated CHANGELOG

Author: rads-1996

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

@@ -3,6 +3,8 @@
 ## 1.6.14 (Unreleased)
 
 ### Features Added
+- Updated README to specify the python version supported by the distro.
+  ([#42464](https://github.com/Azure/azure-sdk-for-python/pull/42464))
 
 ### Breaking Changes
 

sdk/monitor/azure-monitor-opentelemetry/README.md

@@ -43,7 +43,7 @@ To use this package, you must have:
 * Azure subscription - [Create a free account][azure_sub]
 * Azure Monitor - [How to use application insights][application_insights_namespace]
 * Opentelemetry SDK - [Opentelemetry SDK for Python][ot_sdk_python]
-* Python 3.8 or later - [Install Python][python]
+* Python 3.9 or later - [Install Python][python]
 
 ### Install the package