fix(cli): omit flags that aren't in preview from --help output COMPASS-8589 (#7415)

omit flags that aren't in preview from --help output

Author: nvs119

packages/compass-preferences-model/src/preferences-schema.tsx

@@ -1295,6 +1295,8 @@ function featureFlagToPreferenceDefinition(
     global: true,
     ui: true,
     description: featureFlag.description,
+    // Only show feature flags in 'preview' stage in --help output
+    omitFromHelp: featureFlag.stage !== 'preview',
     // if a feature flag is 'released' it will always return true
     // regardless of any persisted value.
     deriveValue: