fix: add empty space to <Checkbox> ring in dark mode (#1160)

The Checkbox now matches the designs outlined in the vanilla Flowbite library.

src/components/Checkbox/theme.ts

@@ -4,7 +4,7 @@ export const checkboxTheme: FlowbiteCheckboxTheme = {
   root: {
     base: 'h-4 w-4 rounded focus:ring-2 border border-gray-300 dark:border-gray-600 dark:bg-gray-700 bg-gray-100',
     color: {
-      default: 'focus:ring-cyan-600 dark:ring-offset-cyan-600 dark:focus:ring-cyan-600 text-cyan-600',
+      default: 'focus:ring-cyan-600 dark:ring-offset-gray-800 dark:focus:ring-cyan-600 text-cyan-600',
       dark: 'focus:ring-gray-800 dark:ring-offset-gray-800 dark:focus:ring-gray-800 text-gray-800',
       failure: 'focus:ring-red-900 dark:ring-offset-red-900 dark:focus:ring-red-900 text-red-900',
       gray: 'focus:ring-gray-900 dark:ring-offset-gray-900 dark:focus:ring-gray-900 text-gray-900',