Merge branch 'jm-change-zoekt-node-critical-limit' into 'master'

Reduce zoekt node critical watermark to 80 percent

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/173580



Merged-by: John Mason <9717668-johnmason@users.noreply.gitlab.com>
Approved-by: Dmitry Gruzd <dgruzd@gitlab.com>
Co-authored-by: John Mason <jmason@gitlab.com>