Micro-edit: spaces not white spaces (#43860)

This PR simplifies a bit of text used in the cache cron schedule component: we can say "spaces" (which is normal English) not "white spaces" (which is developerese)

frontend/src/metabase/admin/settings/components/widgets/ModelCachingScheduleWidget/CronExpressionInput.tsx

@@ -38,7 +38,7 @@ function CustomScheduleInputHint() {
     >{t`cron syntax`}</ExternalLink>
   );
   return (
-    <CustomScheduleLabel>{jt`Our ${cronSyntaxDocsLink} is a string of 5 fields separated by white spaces`}</CustomScheduleLabel>
+    <CustomScheduleLabel>{jt`Our ${cronSyntaxDocsLink} is a string of 5 fields separated by spaces`}</CustomScheduleLabel>
   );
 }