refactor(fetcher): use errors.New when possible instead of fmt.Errorf

internal/reader/fetcher/response_handler.go

@@ -168,7 +168,7 @@ func (r *ResponseHandler) ReadBody(maxBodySize int64) ([]byte, *locale.Localized
 	}
 
 	if len(buffer) == 0 {
-		return nil, locale.NewLocalizedErrorWrapper(fmt.Errorf("fetcher: empty response body"), "error.http_empty_response_body")
+		return nil, locale.NewLocalizedErrorWrapper(errors.New("fetcher: empty response body"), "error.http_empty_response_body")
 	}
 
 	return buffer, nil
@@ -192,11 +192,11 @@ func (r *ResponseHandler) LocalizedError() *locale.LocalizedErrorWrapper {
 
 	switch r.httpResponse.StatusCode {
 	case http.StatusUnauthorized:
-		return locale.NewLocalizedErrorWrapper(fmt.Errorf("fetcher: access unauthorized (401 status code)"), "error.http_not_authorized")
+		return locale.NewLocalizedErrorWrapper(errors.New("fetcher: access unauthorized (401 status code)"), "error.http_not_authorized")
 	case http.StatusForbidden:
-		return locale.NewLocalizedErrorWrapper(fmt.Errorf("fetcher: access forbidden (403 status code)"), "error.http_forbidden")
+		return locale.NewLocalizedErrorWrapper(errors.New("fetcher: access forbidden (403 status code)"), "error.http_forbidden")
 	case http.StatusTooManyRequests:
-		return locale.NewLocalizedErrorWrapper(fmt.Errorf("fetcher: too many requests (429 status code)"), "error.http_too_many_requests")
+		return locale.NewLocalizedErrorWrapper(errors.New("fetcher: too many requests (429 status code)"), "error.http_too_many_requests")
 	case http.StatusNotFound, http.StatusGone:
 		return locale.NewLocalizedErrorWrapper(fmt.Errorf("fetcher: resource not found (%d status code)", r.httpResponse.StatusCode), "error.http_resource_not_found")
 	case http.StatusInternalServerError:
@@ -216,7 +216,7 @@ func (r *ResponseHandler) LocalizedError() *locale.LocalizedErrorWrapper {
 	if r.httpResponse.StatusCode != 304 {
 		// Content-Length = -1 when no Content-Length header is sent.
 		if r.httpResponse.ContentLength == 0 {
-			return locale.NewLocalizedErrorWrapper(fmt.Errorf("fetcher: empty response body"), "error.http_empty_response_body")
+			return locale.NewLocalizedErrorWrapper(errors.New("fetcher: empty response body"), "error.http_empty_response_body")
 		}
 	}