[BUG][GO Server] Syntax error when body is a scalar

Bug Report Checklist

• [ X] Have you provided a full/minimal spec to reproduce the issue?
• [ X] Have you validated the input using an OpenAPI validator (example)?
• [ X] Have you tested with the latest master to confirm the issue still exists?
• [X ] Have you searched for related issues/PRs?
• [ Z] What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

When the body of a request is a scalar, the initialization uses the type{} syntax which is not applicable to scalar, only structs.
Should use new(type) instead.

openapi-generator version

5.3.0

OpenAPI declaration file content or url

Generation Details

Use the openapi-generator-cli bash script
openapi-generator-cli generate -i spec.yaml -g go-server --enable-post-process-file -o src/ -p featureCORS=true,packageName=test,packageVersion=0.0.1

Generates a function like this:

// SampleBug - sampleBug
func (c *DefaultApiController) SampleBug(w http.ResponseWriter, r *http.Request) {
	params := mux.Vars(r)
	jobParam := params["job"]
	
	bodyParam := int32{}
	d := json.NewDecoder(r.Body)
	d.DisallowUnknownFields()
	if err := d.Decode(&bodyParam); err != nil {
		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
		return
	}
...

Steps to reproduce

See above

Related issues/PRs

N/A

Suggest a fix

Should generate something like this for scalars:

// SampleBug - sampleBug
func (c *DefaultApiController) SampleBug(w http.ResponseWriter, r *http.Request) {
	params := mux.Vars(r)
	jobParam := params["job"]
	
	bodyParam := *new(int32)
	d := json.NewDecoder(r.Body)
	d.DisallowUnknownFields()
	if err := d.Decode(&bodyParam); err != nil {
		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
		return
	}
...

Reproduce the issue with the provided OpenAPI declaration and the openapi-generator-cli command using the go-server generator. Inspect the generator path responsible for request-body initialization and compare scalar schemas with struct schemas. Done means the generated Go server initializes scalar bodies without a syntax error and handles the shown request successfully.