chore(Stack): Move Stack component css module feature flag to ga (#5384)

* Move Stack to ga feature flag

* Create plenty-tools-count.md

Author: jonrohan

.changeset/plenty-tools-count.md

@@ -0,0 +1,5 @@
+---
+"@primer/react": patch
+---
+
+Move Stack component css module feature flag to ga

packages/react/src/Stack/Stack.tsx

@@ -7,7 +7,7 @@ import {toggleStyledComponent} from '../internal/utils/toggleStyledComponent'
 import {useFeatureFlag} from '../FeatureFlags'
 import {clsx} from 'clsx'
 
-const CSS_MODULE_FEATURE_FLAG = 'primer_react_css_modules_staff'
+const CSS_MODULE_FEATURE_FLAG = 'primer_react_css_modules_ga'
 
 const StyledStack = toggleStyledComponent(
   CSS_MODULE_FEATURE_FLAG,