Add option to skip Introspection tracing

[liamzhang40]

Thanks for creating this tracer for gqlgen contrib/99designs/gqlgen.

I find it unnecessary to trace the Introspection Query since it creates a huge amount of spans. Can there be an option to disable the tracing of it? Specifically the field spans

We currently wrap around gqlTracer and create a new tracer that looks at the OperationName from gql context and just skips if it is a Introspection query

func (t *wrapperGQLTracer) InterceptField(ctx context.Context, next graphql.Resolver) (any, error) {
	opCtx := graphql.GetOperationContext(ctx)
	if opCtx.OperationName == "IntrospectionQuery" {
		res, err := next(ctx)
		return res, err
	}

	if t, ok := t.baseTracer.(graphql.FieldInterceptor); ok {
		return t.InterceptField(ctx, next)
	}

	res, err := next(ctx)
	return res, err
}

Similar to this DataDog/dd-trace-js#1046

[darccio]

@liamzhang40 We reviewed it, and we wanted to share it's accepted. If you want to contribute, we'll be glad to review and merge your contribution.