createDraftPRs: true doesn't open draft PRs

[FabriceCastel]

I've got createDraftPRs: true in my .spr.yml and all PRs are still getting opened in a non-draft state (the other settings in the config seem to work just fine, so the config is being read from).

Don't really have much else to go off of unfortunately, looked through the repo and that param does seem to get passed through to the GH API call as expected, so I'm not sure what gives..