internal error : without types was imported from

### What happened?
```
gqlgen --verbose
internal error: package "github.com/vektah/gqlparser/v2/ast" without types was imported from "github.com/99designs/gqlgen/graphql/introspection"
```
### What did you expect?
gqlgen work
### Minimal graphql.schema and models to reproduce
[demo](https://github.com/nzlov/godemo)

### versions
- `gqlgen version`? `v0.14.0` or `master`
- `go version`? `go version devel go1.18-adfb85b315 Tue Oct 26 01:22:47 2021 +0000 darwin/amd64`
- dep or go modules? `mod`

错误发生在运行 gqlgen 代码生成时，指向与 gqlparser/v2/ast 相关的导入问题。首先检查链接的演示仓库以复现该问题。查看 go.mod 文件以检查依赖项和版本。使用 verbose 标志运行 gqlgen，以查看完整的堆栈跟踪。调查 introspection 包及其导入，以了解类型缺失的原因。

由索引模型根据 Issue 内容生成。