Chore: remove dead-code configmaps/nfs-cm.yaml and configmaps/nfs/exports

Summary

Two files in the chart are dead code — they have never been rendered by
helm template and no template references them.

Files

• openstudio-server/configmaps/nfs-cm.yaml — at the root of
  configmaps/, not under templates/. helm template only
  renders files under templates/, so this file is never emitted.
  The helm-unittest output and the rendered chart confirm: no
  ConfigMap or nfs-cm reference appears in the rendered output.

• openstudio-server/configmaps/nfs/exports — referenced only by
  the dead nfs-cm.yaml (which uses
  (.Files.Glob "configmaps/nfs/*").AsConfig). Since
  nfs-cm.yaml is never rendered, the contents of this exports
  file are also never used.

Verification

helm template smoketest ./openstudio-server --set provider.name=google | grep -i "kind: ConfigMap"
# (no output)

helm template smoketest ./openstudio-server --set provider.name=google | grep -i "nfs-cm"
# (no output)

Background

The chart started on a helm create scaffold and was hand-rolled
after that. The NFS exports ConfigMap was originally meant to seed
the NFS server provisioner subchart, but the real NFS provisioning
path is the subchart's own PVC + RBAC, not a ConfigMap. The dead
files have been in the repo since the chart's inception and were
spotted during the PR #102 review.

Proposed change

Delete both files in a single chore commit. No template or value
changes; helm template output is byte-identical before and after.

git rm openstudio-server/configmaps/nfs-cm.yaml
git rm openstudio-server/configmaps/nfs/exports
# optionally: remove the now-empty configmaps/nfs/ directory

Out of scope

• The chart's other working NFS bits (templates/nfs/nfs-pvc.yaml,
  the nfs-server-provisioner subchart in Chart.yaml) — these are
  load-bearing and stay.
• Any change to the rendered chart at default values.

Related

• PR #102 review (C2 finding)

Inspect openstudio-server/configmaps/nfs-cm.yaml and openstudio-server/configmaps/nfs/exports, then run the provided helm template and grep commands to confirm neither file contributes rendered output. Remove both files without changing templates or values, and verify the rendered chart remains unchanged and the configmaps/nfs directory is empty or removed.