fixed typo

Author: ericd-mst-github

articles/virtual-machines/image-builder-api-update-release-notes.md

@@ -85,7 +85,7 @@ For API versions 2021-10-01 and newer, the error output will look like the follo
 
 ### Preview APIs
 
- The following APIs is deprecated, but still supported:
+ The following APIs are deprecated, but still supported:
 - 2019-05-01-preview