Salesforce API Error: CANNOT_MODIFY_MANAGED_OBJECT for ValidationRule

I'm encountering an issue modifying a Salesforce Validation Rule via the API. My attempt to update the rule with the ID '03dDn000001evPOIAY' results in the error message:

"Cannot modify managed object: entity=ValidationFormula, component=03dDn000001evPO, field=FieldEnumOrId, state=installed: newValue='null', oldValue='00NDn00000YwUYt'", with errorCode 'CANNOT_MODIFY_MANAGED_OBJECT'.

Here's my code snippet

from simple_salesforce import Salesforce

try:
    # Establish Salesforce connection
    sf = Salesforce(username='***********', password='********', security_token='********')

    # Query using the Tooling API to get the validation rule
    tooling_query = ("SELECT Id, CreatedDate, CreatedBy.Name, EntityDefinition.DeveloperName, ValidationName, Active "
                     "FROM ValidationRule WHERE ValidationName = 'Require_Default_Consignor'")
    response = sf.restful('tooling/query', params={'q': tooling_query})

    # Check if the query returned any records
    if response['records']:
        record = response['records'][0]
        validation_rule_id = record['Id']
        print("Connection successful. Retrieved validation rule:")
        print(f"ID: {validation_rule_id}")
        print(f"Created Date: {record['CreatedDate']}")
        print(f"Validation Name: {record['ValidationName']}")
        print(f"Active: {record['Active']}")

        # Prepare the metadata for update
        metadata = {
            "description": "Updated via Python Script",  # Include your desired description here
            "active": True,  # Set the active state
            "errorConditionFormula": "NOT(ISNULL(ValidationName))",
            "errorMessage": "Error updating somecolumn."
        }

        # Update the Validation Rule using PATCH method with the metadata
        update_response = sf.restful(f'tooling/sobjects/ValidationRule/{validation_rule_id}',
                                     method='PATCH', json={'Metadata': metadata})

        print("Validation rule updated successfully.")
    else:
        print("Connection successful but no validation rules found.")
except Exception as e:
    print("Error occurred:", e)

Any guidance on resolving this CANNOT_MODIFY_MANAGED_OBJECT error would be greatly appreciated.