Planning next release (v17)

[consideRatio]

There is one one breaking change is in main currently (#735), so next release should be v17.

Things to get done

• Make headings etc in changelog consistent #754
• Update references from unreleased v16.4 to upcoming v17.0 #755
• New group config in OAuthenticator overlaps with allowed_google_groups for example and may not work - what do we do? #756
  • Fixed by Various fixes for allowed_groups and admin_groups #758

Changes to summarize in changelog

See #756 (comment)