Multipart section with '$ref' showing as required even when it's not

[bart-acc]

When loading the following reproducer in RapiDoc

{
    "openapi": "3.1.0",
    "info": {
        "title": "minimal example",
        "description": "of a section not being required but rendering as if it was",
        "license": {
            "name": "Proprietary"
        },
        "version": "0.0.1"
    },
    "paths": {
		"/minimal_json": {
            "post": {
                "tags": ["example"],
                "summary": "example of the problem",
                "description": "the not required field shows as if it's required",
                "operationId": "with_presentation_value",
                "requestBody": {
                    "content": {
                        "application/json": {
                            "schema": {
                                "$ref": "#/components/schemas/MinimalRequest"
                            }
                        }
                    },
                    "required": true
                }
            }
        },
        "/minimal_multipart": {
            "post": {
                "tags": ["example"],
                "summary": "example of the problem",
                "description": "the not required field shows as if it's required",
                "operationId": "with_presentation_value",
                "requestBody": {
                    "content": {
                        "multipart/form-data": {
                            "schema": {
                                "$ref": "#/components/schemas/MinimalRequest"
                            }
                        }
                    },
                    "required": true
                }
            }
        }
    },
    "components": {
        "schemas": {
            "MinimalRequest": {
                "type": "object",
                "required": ["section_1_1","section_2_1"],
                "properties": {
                    "section_1_1": {
                        "type": "string",
                        "description": "required"
                    },
					"section_1_2": {
                        "type": "string",
                        "description": "not required"
                    },
                    "section_2_1": {
                        "$ref": "#/components/schemas/MinimalRequestOptions",
                        "description": "required"
                    },
					"section_2_2": {
                        "$ref": "#/components/schemas/MinimalRequestOptions",
                        "description": "not required"
                    }
                }
            },
            "MinimalRequestOptions": {
                "type": "object",
                "required": ["member_1"],
                "properties": {
                    "member_1": {
                        "type": "boolean",
                        "description": "a bool, required"
                    },
					"member_2": {
                        "type": "boolean",
                        "description": "another bool, not required"
                    }
                }
            }
        }
    }
}

When looking at the schema of /minimal_json everything is correctly rendered as required or not. However when looking at /minimal_multipart section_2_2 is shown as required (the red star/* next to its name) while it's clearly not marked as such in the api description json.