[Project Solar / Phase 1 / Cherry-pick] Added missing await to async function in generateCssHelpers.ts (#3560)

Author: didoo

packages/tokens/scripts/build-parts/generateCssHelpers.ts

@@ -17,7 +17,7 @@ export const PREFIX = 'hds';
 
 export async function generateCssHelpers(dictionary: Dictionary, config: PlatformConfig ): Promise<void> {
 
-  fs.ensureDir(`${config.buildPath}helpers/`);
+  await fs.ensureDir(`${config.buildPath}helpers/`);
 
   const header = await fileHeader({});