fix(aws-serverless): Include ESM artifacts in package (#11973)

Fix the `files` property in our AWS Serverless SDK
`package.json` to include ESM artifacts now that we support ESM in AWS
Serverless.

Author: Lms24

packages/aws-serverless/package.json

@@ -11,6 +11,7 @@
   },
   "files": [
     "cjs",
+    "esm",
     "types",
     "types-ts3.8",
     "import-hook.mjs",