Fix the blueprint for pydantic version 2

[caarmen]

Use the proper ref_template, specifying the {model} in the template.

An example is documented here: https://github.com/pydantic/pydantic/blob/main/docs/usage/json_schema.md#schema-customization

We need to specify ref_template = '#/components/schemas/{model}', not ref_template = '#/components/schemas/' (need that extra {model} at the end).

model_json_schema generates something like this, for a Parent model with a child field of type Child:

{
    "$defs": {
        "Child": {
            "properties": {
                "foo": {
                    "default": 5,
                    "title": "Foo",
                    "type": "integer"
                }
            },
            "title": "Child",
            "type": "object"
        }
    },
    "properties": {
        "child": {
            "anyOf": [
                {
                    "$ref": "#/components/schemas/Child"
                },
                {
                    "type": "null"
                }
            ],
            "default": null
        }
    },
    "title": "Parent",
    "type": "object"
}

The definitions are in a key $defs (not definitions), and the references start with #/components/schemas as expected.

[caarmen]

Please feel free to test it out. I only tested on a very simple case specific to my project.

Thanks! 🙏🏻

[codecov]

Codecov Report

Patch and project coverage have no change.

Comparison is base (b7f79b7) 98.55% compared to head (d1b874a) 98.55%.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1030   +/-   ##
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  Coverage   98.55%   98.55%           
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  Files          68       68           
  Lines        8367     8367           
=======================================
  Hits         8246     8246           
  Misses        121      121           

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[devanubis]

Hi, this seems to partly fix my problems (#1105).

But it's not picking up nested models, e.g. the example test case from this old comment.

I'm going to try to see if I can get the extension to dive into nested $defs and add them as components too.

Turns out it works just fine 🎉 I had two extensions in scope from debugging attempts 🤦.

[tfranzel]

I suppose I'll merge it then. Almost forgot about it.