Overridden serialization methods doesn't work in JSON Schema for optional fields and inner dataclasses

[Fatal1ty]

• mashumaro version: 3.9
• Python version: 3.11
• Operating System: MacOS 13.3.1

Description

When you override serialization method through serialization_strategy or field metadata as noted here for dataclass type or any type that is used inside Optional, this method's return type is not reflected in JSON Schema.

What I Did

First example:

from dataclasses import dataclass
from mashumaro.config import BaseConfig
from mashumaro.jsonschema import build_json_schema

def dataclass_serialize(value) -> str:
    return str(value)

@dataclass
class Bar:
    x: int

@dataclass
class Foo:
    bar: Bar

    class Config(BaseConfig):
        serialization_strategy = {
            Bar: {"serialize": dataclass_serialize},
        }

print(build_json_schema(Foo).to_json())

Actual result

{
    "type": "object",
    "title": "Foo",
    "properties": {
        "bar": {
            "type": "object",
            "title": "Bar",
            "properties": {
                "x": {
                    "type": "integer"
                }
            },
            "additionalProperties": false,
            "required": [
                "x"
            ]
        }
    },
    "additionalProperties": false,
    "required": [
        "bar"
    ]
}

Expected result

{
    "type": "object",
    "title": "Foo",
    "properties": {
        "bar": {
            "type": "string"
        }
    },
    "additionalProperties": false,
    "required": [
        "bar"
    ]
}

Second example:

from typing import Optional
from dataclasses import dataclass
from mashumaro.config import BaseConfig
from mashumaro.jsonschema import build_json_schema

def int_serialize(value) -> str:
    return str(value)

@dataclass
class Foo:
    bar: Optional[int]

    class Config(BaseConfig):
        serialization_strategy = {
            int: {"serialize": int_serialize},
        }

print(build_json_schema(Foo).to_json())

Actual result

{
    "type": "object",
    "title": "Foo",
    "properties": {
        "bar": {
            "anyOf": [
                {
                    "type": "integer"
                },
                {
                    "type": "null"
                }
            ]
        }
    },
    "additionalProperties": false,
    "required": [
        "bar"
    ]
}

Expected result

{
    "type": "object",
    "title": "Foo",
    "properties": {
        "bar": {
            "anyOf": [
                {
                    "type": "string"
                },
                {
                    "type": "null"
                }
            ]
        }
    },
    "additionalProperties": false,
    "required": [
        "bar"
    ]
}