fix: remove globalThis check and align with what bundlers can accept

src/jsutils/instanceOf.ts

@@ -1,5 +1,14 @@
 import { inspect } from './inspect';
 
+/* c8 ignore next 4 */
+const isProduction =
+ // eslint-disable-next-line no-undef
+ typeof process !== 'undefined' &&
+ // eslint-disable-next-line no-undef
+ process.env &&
+ // eslint-disable-next-line no-undef
+ process.env.NODE_ENV === 'production';
+
 /**
  * A replacement for instanceof which includes an error warning when multi-realm
  * constructors are detected.
@@ -9,7 +18,7 @@ import { inspect } from './inspect';
 export const instanceOf: (value: unknown, constructor: Constructor) => boolean =
  /* c8 ignore next 6 */
  // FIXME: https://github.com/graphql/graphql-js/issues/2317
- globalThis.process && globalThis.process.env.NODE_ENV === 'production'
+ isProduction
  ? function instanceOf(value: unknown, constructor: Constructor): boolean {
  return value instanceof constructor;
  }