ansible creating nested structure from inventory

I am trying to create this data structure in ansible.

 permissions:
      - vhost: /aws-replica001
        configure_priv: .*
        read_priv: .*
        write_priv: .*
      - vhost: /aws-replica004
        configure_priv: .*
        read_priv: .*
        write_priv: .*
      - vhost: /aws-replica005
        configure_priv: .*
        read_priv: .*
        write_priv: .*

#
# my code
#
- name: set permissions
  set_fact:
    perms: "{{ groups['ingestion'] | map ({'vhost' : item}) | list }}"
    
#
# result at runtime
#
TASK [rabbitmq : set permissions] **********************************************************************************************************************************************
fatal: [aws-dbtest.dev.thesyscat.com]: FAILED! => {"msg": "Unexpected templating type error occurred on ({{ groups['ingestion'] | map ({'vhost' : item}) | list }}): unhashable type: 'dict'"}
  

I am told this fails because the map filter can only take another filter as argument.