fix: standardise checkboxes

Checkboxes were previously styled super wonky due to
the usage of checkboxClassName which styled the checkbox
trigger.

This change reverts all that and leaves it with sensible defaults
across dark and light mode.

packages/ui/primitives/template-flow/add-template-fields.tsx

@@ -587,7 +587,6 @@ export const AddTemplateFieldsFormPartial = ({
                         <Checkbox
                           {...field}
                           id="typedSignatureEnabled"
-                          checkClassName="text-white"
                           checked={value}
                           onCheckedChange={(checked) => field.onChange(checked)}
                           disabled={form.formState.isSubmitting}