fix: batch selector flag (#31191)

This is broken again after serializing scan actions, which causes
selector to trigger before batch_no is set.

Solution: for duration of scan disable the selector

erpnext/public/js/controllers/transaction.js

@@ -526,12 +526,6 @@ erpnext.TransactionController = class TransactionController extends erpnext.taxe
 											if(!d[k]) d[k] = v;
 										});
 
-										if (d.__disable_batch_serial_selector) {
-											// reset for future use.
-											d.__disable_batch_serial_selector = false;
-											return;
-										}
-
 										if (d.has_batch_no && d.has_serial_no) {
 											d.batch_no = undefined;
 										}