Cleaning cache problem

[EreminAnton]

If the request fails before "cache_for_dublicate_requests.clear()" happens, that cache will persist and will stop users from creating new requests until the refresh of lambda's environment.
Consider cleaning the cache after sending a message to the user about an error: https://github.com/fivexl/terraform-aws-sso-elevator/blob/main/src/main.py#L39