Fix extendGraphqlSchema so custom resolvers override the default

[borisno2]

Closes #7527

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🦋 Changeset detected

Latest commit: 1c18ecd

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 15 packages

Name	Type
@keystone-6/core	Minor
@keystone-6/auth	Major
@keystone-6/cloudinary	Major
@keystone-6/fields-document	Major
@keystone-6/session-store-redis	Major
@keystone-6/example-auth	Patch
@keystone-6/examples-app-basic	Patch
@keystone-6/example-ecommerce	Patch
@keystone-6/example-graphql-api-endpoint	Patch
@keystone-6/example-roles	Patch
@keystone-6/example-testing	Patch
@keystone-6/example-with-auth	Patch
@keystone-6/sandbox	Patch
@keystone-6/website	Patch
@keystone-6/example-document-field	Patch

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Name	Status	Preview	Updated
keystone-next-docs	✅ Ready (Inspect)	Visit Preview	Jun 21, 2022 at 4:31AM (UTC)

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