Nested disconnect fails on MongoDB with extendedWhereUnique

[Weakky]

Bug description

Consider this datamodel

model Parent {
  id Int @id

  childId Int? @unique
  childOpt Child? @relation(fields: [childId], references: [id])
}

model Child {
  id Int @id
  non_unique String
  parentOpt Parent?
}

And say you run this query

await prisma.parent.update({
  where: { id: 1 },
  data: {
    childOpt: { disconnect: { non_unique: 1 } }
  }
})

The query will fail because MongoDB doesn't render the join required to filter on Child.non_unique.

Expected behavior

It looks impossible to perform updates based on filters that require joining foreign collections.
We might need to remove the ability to filter (for disconnect) on MongoDB when the relation field being filtered isn't inlined on the enclosing model.

Environment & setup

• OS: macOS
• Database: Postgres 10

Prisma Version

4.7.0

[Weakky]

Related to #15837