Unable to define NUll in Ansible set_fact

gistfile1.txt

# mariadb sql table includes the following column
`date_of_removal` datetime DEFAULT NULL,


# The Key Dict is either 
'main_dict.removal_info is defined': '2021-12-19 21:50:43'  # a datetime properly formated  
'main_dict.removal_info is defined': 'N/A'  # A string 

# The goal is to properly provide a Null when 'N/A' is present

# Meanwhile in Ansible set_fact

- name: Set the etl_dictionary Key Value Dictionary from main_dict request 
  set_fact:
    etl_dictionary: >-
          {
 
           {% if main_dict.removal_info is defined -%} 
            {% if 'N/A' in main_dict.removal_info  -%}
                "date_of_removal": 'Null' ,
              {% else %}
                "date_of_removal": "{{main_dict.removal_info}}",
            {% endif %} 
          {% endif %} 
            
          }
 
 # SQL Statement 
 # Cannot execute SQL 'INSERT INTO .... 'N/A', 'No', 'null', 'N/A'
The expected behaviour to achieve is  ... 'N/A', 'No', Null, 'N/A'

TASK [cert_discovery : Debug certs output] *********************************************************************************************************************************************************
Wednesday 15 December 2021  07:32:27 -0500 (0:00:00.058)       0:00:00.998 **** 
ok: [localhost] => {
    "etl_dictionary": {
        "date_of_removal": null
    }
}

TASK [cert_discovery : Print the etl_dictionary Columns and Keys] **********************************************************************************************************************************
Wednesday 15 December 2021  07:32:27 -0500 (0:00:00.050)       0:00:01.048 **** 
ok: [localhost] => {
    "msg": "(date_of_removal) VALUES (None)"
}


TASK [cert_discovery : Insert  etl_dictionary to our etl_in_cert_scanner DataBase] ***********************************************************************************************************
Wednesday 15 December 2021  07:32:27 -0500 (0:00:00.056)       0:00:01.105 **** 
fatal: [localhost]: FAILED! => {"changed": false, "msg": "Cannot execute SQL 'INSERT INTO etl_in_cert_scanner ( date_of_removal ) VALUES ( 'None' )' args [None]: (1292, u\"Incorrect datetime value: 'None' for column `certmgmt_lst`.`etl_in_cert_scanner`.`date_of_removal` at row 1\")"}
...ignoring