The S3 bucket that stores the website contents defined in :/aws/website_cfn.yml uses the AccessControl: Private property, this is now considered a legacy property and "shouldn't be used".
https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-s3-bucket.html#cfn-s3-bucket-accesscontrol
Migrating to a bucket policy is the solution, however it's not immediately clear what policy would correctly replace the old ACL configuration without breaking other things.
The S3 bucket that stores the website contents defined in
:/aws/website_cfn.ymluses theAccessControl: Privateproperty, this is now considered a legacy property and "shouldn't be used".https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-s3-bucket.html#cfn-s3-bucket-accesscontrol
Migrating to a bucket policy is the solution, however it's not immediately clear what policy would correctly replace the old ACL configuration without breaking other things.