fix(gitea-api): authorize for issues in private repositories / organizations

This also fixes an issue with the taskwarrior filters to not overwrite
existing other tasks from other repositories.

internal/taskwarrior/task.go

@@ -113,7 +113,6 @@ func GetTasks(filter Filter) ([]Task, error) {
 	}
 	var tasks []Task
 	decoder := json.NewDecoder(bytes.NewBuffer(out))
-	decoder.DisallowUnknownFields()
 	if err = decoder.Decode(&tasks); err != nil {
 		return nil, err
 	}