Attachments are not supported for your environment SKU, Teams.
This error "Attachments are not supported for your environment SKU, Teams. To interact with Approvals attachments, please use an environment with a SKU that is not Teams." occurs while using the Approval Action
with attachment inside a flow that created in an environment for teams.
Due to the limitations or restrictions within Teams environment, unfortunately you can't perform this for now in Teams environment, and instead, you have to use an environment with a SKU that is not for Teams!