Unknown directive "@oneOf".

[sonewman]

Issue Description

This results in error, it fails at printSubgraphSchema no clue why, some validation step that can't be avoided. Schema seems to be valid when built into subgraph, composes fine.... just can't be printed

import { buildSubgraphSchema, printSubgraphSchema } from "@apollo/subgraph";
import * as GraphQL from "graphql";

const schema = buildSubgraphSchema([
  {
    typeDefs: GraphQL.parse(/* GraphQL */ `
    directive @oneOf on INPUT_OBJECT

    type Mutation {
      dummy(input: OneOfInput): String
    }

    input OneOfInput @oneOf {
      field1: String
      field2: String
    }
  `),
  },
]);

printSubgraphSchema(schema);

I am using

    "@apollo/subgraph": "^2.14.0",
    "graphql": "^16.14.0",

Link to Reproduction

Reproduction Steps

No response

[nedredmond]

Ran into this today. Huge bummer I can't use this feature.