Add changelog entries from botocore

Author: aws-sdk-python-automation

.changes/next-release/feature-sts-68158.json

@@ -0,0 +1,5 @@
+{
+  "type": "feature",
+  "category": "``sts``",
+  "description": "Updated the default sts service endpoint from ``legacy`` to ``regional``. This behavior can be overridden using the ``sts_regional_endpoints`` setting in the shared AWS config file or the ``AWS_STS_REGIONAL_ENDPOINTS`` environment variable."
+}