Can we disable unknown field validation error GRAPHQL_VALIDATION_FAILED?

### What happened?
We are migrating from graph-gophers to gqlgen. It is the end of the migration now, but we are blocked by seeing such errors often. The graph-gophers library will ignore unknown fields. Our frontend sometimes sends unknown fields still and there are just too many fields to remove. Is there a way to disable this error?

```json
{
"message": "unknown field",
"path": ["blabla"],
"extensions": {
"code": "GRAPHQL_VALIDATION_FAILED"
}
}
```

### What did you expect?

I would like a way to config gqlgen and disable this error.

### versions
- `go run github.com/99designs/gqlgen version`? v0.17.20
- `go version`? 1.19.1

查看 gqlgen 代码库中的验证逻辑，可能位于 validation 或 execution 包中。搜索 GRAPHQL_VALIDATION_FAILED 以及未知字段的处理。目标是添加一个配置选项以禁用未知字段验证，同时保持向后兼容性。检查现有的配置结构，并了解验证错误是如何生成和返回的。

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