Cant post GitHub-Issues

[Adrian Preuß]

If you try to post a Bug on New Issue on the GitHub Repository, following Error appears:

On Network-Inspector,  following response is given:

```
{
    "data": {
        "createIssue": {
            "issue": null,
            "errors": [
                {
                    "__typename": "ValidationError",
                    "message": "could not be created. Interactions on this repository have been restricted to prior contributors only."
                }
            ]
        }
    },
    "errors": [
        {
            "type": "UNPROCESSABLE",
            "path": [
                "createIssue"
            ],
            "locations": [
                {
                    "line": 5,
                    "column": 3
                }
            ],
            "message": "could not be created. Interactions on this repository have been restricted to prior contributors only."
        }
    ],
    "extensions": {
        "warnings": [
            {
                "type": "DEPRECATION",
                "message": "The id MDEwOlJlcG9zaXRvcnk4MDU0NjE= is deprecated. Update your cache to use the next_global_id from the data payload.",
                "data": {
                    "legacy_global_id": "MDEwOlJlcG9zaXRvcnk4MDU0NjE=",
                    "next_global_id": "R_kgDOAAxKVQ"
                },
                "link": "https://docs.github.com"
            }
        ],
        "query_owning_catalog_service": "issues_experience"
    }
}
```

Why, the Issue-Posting is restricted to contributors?