### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

When performing any requests with path parameters with validation enabled the following error message is returned

`GET http://localhost:4566/restapis/<apigw_id>/local/_user_request_/test/world`

returns

`{"Type": "User", "message": "Invalid request body", "__type": "InvalidRequest"}`

### Expected Behavior

Path parameter validation works like AWS, i.e. validation is performed, lambda is invoked and response returned to caller.

`GET http://localhost:4566/restapis/<apigw_id>/local/_user_request_/test/world`

returns

`"hello world"`

### How are you starting LocalStack?

With the `localstack` script

### Steps To Reproduce

#### How are you starting localstack (e.g., `bin/localstack` command, arguments, or `docker-compose.yml`)

    localstack start

#### Client commands (e.g., AWS SDK code snippet, or sequence of "awslocal" commands)

   See project in zip archive - [localstack-path-parameter-test.zip](https://github.com/localstack/localstack/files/10952340/localstack-path-parameter-test.zip). Also included below.

To deploy to localstack:

1. `yarn install`
2. `npx sls deploy --stage local --region eu-west-2`


This has two endpoints. The first, test, works but the second endpoint, broken-test, fails with the error `Invalid request body`.

It looks like the error is caused by localstack not being able to handle `AWS::ApiGateway::RequestValidator` correctly.

Also if you try to fix an endpoint by removing the validation, i.e. change the broken-test endpoint to:

```
  broken-test:
    handler: handler.test
    events:
      - http:
          path: broken-test/{value}
          method: get
```

Then after deploying and hitting this endpoint you get an error like

```
{
"__type": "InternalError",
"message": "exception while calling apigateway with unknown operation: An error occurred (NotFoundException) when calling the GetRequestValidator operation: Validator 06ce6f for API Gateway 5ajrq316ln not found"
}
```


**serverless.yml**
```
service: locastack-test
provider:
  name: aws
  runtime: nodejs16.x
  environment:
    NODE_ENV: dev
plugins:
  - serverless-localstack
custom:
  localstack:
    stages: [local]
    host: http://127.0.0.1
    debug: true
functions:
  test:
    handler: handler.test
    events:
      - http:
          path: test/{value}
          method: get
  broken-test:
    handler: handler.test
    events:
      - http:
          path: broken-test/{value}
          method: get
          request:
            parameters:
              paths:
                issuer: true
```

**handler.js**
```
exports.test = async function (event, context) {
  return {
    body: `hello ${event.pathParameters.value}`,
    headers: {},
    statusCode: 200,
  };
}
```

**package.json**
```
{
  "name": "localstack-test",
  "devDependencies": {    
    "serverless": "^3.28.1",
    "serverless-localstack": "^1.0.4"
  }
}
```

### Environment

```markdown
- OS: AWS Linux Workspace
- LocalStack: latest
```


### Anything else?

[localstack_logs.txt](https://github.com/localstack/localstack/files/10952376/localstack_logs.txt)

self,
        context: RequestContext,
        rest_api_id: String,
        location: DocumentationPartLocation,
        properties: String,
    ) -> DocumentationPart:
        entity_id = short_uid()[:6]  
        store = get_apigateway_store(account_id=context.account_id, region=context.region)
        if not (rest_api_container := store.rest_apis.get(rest_api_id)):
            raise NotFoundException(
                f"Invalid API identifier specified {context.account_id}:{rest_api_id}"
            )
        doc_part = DocumentationPart(
            id=entity_id,
            location=location,
            properties=properties,
        )
        rest_api_container.documentation_parts[entity_id] = doc_part
        result = to_documentation_part_response_json(rest_api_id, doc_part)
        return DocumentationPart(**result)
    def update_documentation_part(