Fix edge executor UI navigation when behind reverse proxy with subpath (#63777)

The /api/v2/version call in NavTabs used a hardcoded absolute path,
  which 404s when Airflow is served under a subpath (e.g. /airflow/).
  This prevented the nav tabs from rendering, forcing users to navigate
  via inline table links that lacked relative=path, causing URLs to
  append instead of replace (e.g. /worker/jobs/worker/...).