Lazy List was not being created due to `field.primaryKey` not returning true for Post4V2

[lawmicha]

bug where lazy List was not being created due to field.primaryKey of the generated code was not returning true for Post4V2. this change can be applied directly on main and cherry picked over to v1.

Originally posted by @lawmicha in #2448 (comment)

[github-actions]

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[lawmicha]

I opened this issue without actually reproducing this change from main so it might have been a bug that I introduced and fixed in the PR. The PR #2583 is pretty far along now, so if the issue does exist on main, it will be fixed with the release of the PR.