fix docs build + remove rc versions + add nav json for 0.11.16

Summary: the bug was in the update_version.py where the _versioned_navigation.json wasn't updated properly

Test Plan:
yarn dev, yarn build
bk

Reviewers: sashank, sidkmenon

Reviewed By: sidkmenon

Differential Revision: https://dagster.phacility.com/D8683