FYI, this was fixed in 1.60.0, per the release notes.
In version 1.59.0 the password is now optional when creating or updating a user.
When returning from a third-party login, a user may be prompted to complete registration by entering a password when self-service is enabled and is configured to require a password.
This was unintended and has been corrected.
https://fusionauth.io/docs/release-notes/
Tracking issue: https://github.com/FusionAuth/fusionauth-issues/issues/3159