Drop the stale note about arming the build trigger

The warning dated from when .build-host was the release trigger's own setting
and push was a second consumer of it. One setting now names one machine for all
three commands, so there is nothing to keep separate -- and the advice was
wrong regardless: OMARCHY_REPO_HOST is read by the same resolver, so it arms
the trigger exactly as the file does. Only --host is per-invocation.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

helpers/host-helpers.sh

@@ -39,7 +39,4 @@ print_no_repo_host() {
   echo ""
   echo "Pass --host, set OMARCHY_REPO_HOST, or write the destination to:"
   echo "  $BUILD_ROOT/.repo-host"
-  echo ""
-  echo "That file also arms the automatic build trigger in 'bin/omarchy-pkgs"
-  echo "release'. Use --host or OMARCHY_REPO_HOST to keep them separate."
 }