Error Tracking: Fix collecting errors for golang

What does this MR do and why?

The current JSON schema for error events does not correctly validate Go error events, as implemented here: !72050 (merged)

How to set up and validate locally

package main

import (
	"fmt"
	"log"
	"time"

	"github.com/getsentry/sentry-go"
)

func main() {
	if err := sentry.Init(sentry.ClientOptions{
		Dsn:   "https://key@gitlab.com/api/v4/error_tracking/collector/...",
		Debug: true,
	}); err != nil {
		fmt.Printf("Sentry initialization failed: %v\n", err)
	}
	log.Println(sentry.CaptureException(fmt.Errorf("test")))
	log.Println(sentry.Flush(1 * time.Second))
}

See https://gitlab.com/splattael/error-tracking-example-golang/

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.