docs(polly-request-presigner): update NPM badge (#3686)

Author: AllanZhengYP

Diff for: packages/polly-request-presigner/README.md

@@ -1,7 +1,7 @@
 # @aws-sdk/polly-request-presigner
 
 [![NPM version](https://img.shields.io/npm/v/@aws-sdk/polly-request-presigner/latest.svg)](https://www.npmjs.com/package/@aws-sdk/polly-request-presigner)
-[![NPM downloads](https://img.shields.io/npm/dm/@aws-sdk/polly-request-presigner/beta.svg)](https://www.npmjs.com/package/@aws-sdk/polly-request-presigner)
+[![NPM downloads](https://img.shields.io/npm/dm/@aws-sdk/polly-request-presigner.svg)](https://www.npmjs.com/package/@aws-sdk/polly-request-presigner)
 
 This package provides a presigner based on signature V4 that will attempt to
 generate signed url for polly audio.