As reported by @hansod1 in github.com/99designs/gqlgen#3693
When in #291 we added the token limit, we should have used gqlerror to be more consistent
For reference, here is the change in gqlparser that added the new error.

As a result, the error is not as easy to detect as being from the parser because this part of the gqlgen codebase does not correctly interpret the token limit error as a parsing error because it is not returned from the parser as a *gqlerror.Error, and rather is an errors.errorString created with fmt.Errorf:

	doc, err := parser.ParseQueryWithTokenLimit(&ast.Source{Input: query}, e.parserTokenLimit)
	if err != nil {
		gqlErr, ok := err.(*gqlerror.Error)
		if ok {
			errcode.Set(gqlErr, errcode.ParseFailed)
			return nil, gqlerror.List{gqlErr}
		}
	}

We should add a lint rule that bans fmt.Errorf and adds nolint comments for our remaining uses in our panics but I only got 3 hours of sleep so not doing that now.

Signed-off-by: Steve Coffman steve@khanacademy.org