clarify the feature is not available on oss

docs/integrations/sources/s3.md

@@ -62,10 +62,15 @@ Your `Secret Access Key` will only be visible once upon creation. Be sure to cop
 For more information on managing your access keys, please refer to the
 [official AWS documentation](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_credentials_access-keys.html).
 
-<!-- env:cloud -->
 
 #### Option 2: Using an IAM Role (Most secure)
 
+<!-- env:oss -->
+:::note
+S3 authentication using an IAM role member is not supported using the OSS platform.
+<!-- /env:oss -->
+
+<!-- env:cloud -->
 
 :::note
 S3 authentication using an IAM role member must be enabled by a member of the Airbyte team. If you'd like to use this feature, please [contact the Sales team](https://airbyte.com/company/talk-to-sales) for more information.