[BUG] typescript generator throws when `additionalProperties` is set to `true`

Created by: arnemolland

Bug Report Checklist

Have you provided a full/minimal spec to reproduce the issue?
Have you validated the input using an OpenAPI validator (example)?
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Description

When using the typescript generator, anywhere additionalProperties is explicitly set to true, the generator throws. It should be expected with array types, but this happens on object types. This is not the case with the typescript-axios or typescript-fetch generators. It does not throw when additionalProperties is set to false or if it's omitted (in which case I've interpreted the spec as to it's true by default).

openapi-generator version

6.0.1

OpenAPI declaration file content or url

Repro JSON schema

{
    "openapi": "3.0.3",
    "components": {
        "schemas": {
            "foo": {
                "properties": {
                    "bar": {
                        "additionalProperties": true,
                        "description": "baz",
                        "type": "object"
                    }
                },
                "type": "object"
            }
        }
    },
    "info": {
        "title": "Repro",
        "version": "1.0.0"
    },
    "paths": {
        "/": {
            "get": {
                "description": "Foo",
                "operationId": "getFoo",
                "responses": {
                    "200": {
                        "content": {
                            "application/json": {
                                "schema": {
                                    "properties": {
                                        "foo": {
                                            "description": "Foo.",
                                            "type": "string"
                                        }
                                    },
                                    "required": [
                                        "foo"
                                    ],
                                    "type": "object"
                                }
                            }
                        },
                        "description": "Foo"
                    }
                },
                "summary": "Foo",
                "tags": [
                    "metadata"
                ]
            }
        }
    }
}

Generation Details

openapi-generator-cli generate -i spec.json -g typescript -o /dev/null

Steps to reproduce

Use the typescript generator to generate code from any schema where any components.schemas.properties object has additionalProperties set to true.

Logs

Exception in thread "main" java.lang.RuntimeException: Could not process model 'errorAuthenticatorAssuranceLevelNotSatisfied'.Please make sure that your schema is correct!
        at org.openapitools.codegen.DefaultGenerator.generateModels(DefaultGenerator.java:509)
        at org.openapitools.codegen.DefaultGenerator.generate(DefaultGenerator.java:911)
        at org.openapitools.codegen.cmd.Generate.execute(Generate.java:465)
        at org.openapitools.codegen.cmd.OpenApiGeneratorCommand.run(OpenApiGeneratorCommand.java:32)
        at org.openapitools.codegen.OpenAPIGenerator.main(OpenAPIGenerator.java:66)
Caused by: java.lang.ClassCastException: class java.lang.Boolean cannot be cast to class io.swagger.v3.oas.models.media.Schema (java.lang.Boolean is in module java.base of loader 'bootstrap'; io.swagger.v3.oas.models.media.Schema is in unnamed module of loader 'app')
        at org.openapitools.codegen.languages.TypeScriptClientCodegen.getTypeDeclaration(TypeScriptClientCodegen.java:890)
        at org.openapitools.codegen.DefaultCodegen.fromProperty(DefaultCodegen.java:3650)
        at org.openapitools.codegen.DefaultCodegen.addVars(DefaultCodegen.java:5402)
        at org.openapitools.codegen.DefaultCodegen.addVars(DefaultCodegen.java:5344)
        at org.openapitools.codegen.DefaultCodegen.updateModelForObject(DefaultCodegen.java:2672)
        at org.openapitools.codegen.DefaultCodegen.fromModel(DefaultCodegen.java:2873)
        at org.openapitools.codegen.DefaultGenerator.processModels(DefaultGenerator.java:1288)
        at org.openapitools.codegen.DefaultGenerator.generateModels(DefaultGenerator.java:504)
        ... 4 more