Fix crash in node when mixing sync/async resolvers (backport of #3529)

[chrskrchr]

This is a backport of ~#3529~ #3651 to the 15.x branch that fixes #3528.

Full credit to @asztal for identifying the fix and submitting the original PR.

[linux-foundation-easycla[bot]]

The committers listed above are authorized under a signed CLA.

• :white_check_mark: login: chrskrchr / name: Chris Karcher (651fc3f3eec7d1f92423f2e36e8f93c219cb4f03, b9dc10cfc407de71e590650782b651bede061475, cd9b7b5e771e763a70a078112ad3c0bb853515d3)

[chrskrchr]

Working through the CLA authorization now.

[chrskrchr]

Moving this PR back to draft while I sort out the typing issues.

[chrskrchr]

Also please backport it to v16. It would be strange to have this fix in v15 and v17 but not v16 :)

Thanks for the heads up! I wasn't aware that main had moved on to v17. Submitted a similar PR for 16.x.x here:

https://github.com/graphql/graphql-js/pull/3576

[chrskrchr]

@IvanGoncharov - I finally worked through the EasyCLA issues, would you mind taking another look at this PR?

[chrskrchr]

Closing this and re-submitting as a new PR per the guidance in #3651.