fix: added text white color to dark theme variables

Author: shayan-deriv

lib/styles/base/_root.scss

@@ -250,6 +250,7 @@
         --du-text-info-blue-background: #{$color-blue-7};
         --du-text-status-info-blue: #{$color-blue};
         --du-text-hint: #{$color-gray};
+        --du-text-white: #{$color-white};
         --du-icon-light-background: #{$color-black-9};
         --du-icon-dark-background: #{$color-white};
         --du-icon-gray-background: #{$color-black-1};