fix: for pos, paid amount has not considered the tax amount due to which outstanding amount showing for the pos invoices (#19039)

diff --git a/erpnext/accounts/page/pos/pos.js b/erpnext/accounts/page/pos/pos.js
index 2173e7d..0cd8bfe 100755
--- a/erpnext/accounts/page/pos/pos.js
+++ b/erpnext/accounts/page/pos/pos.js
@@ -1691,20 +1691,13 @@
 
 		if(this.si_docs) {
 			this.si_docs.forEach((row) => {
-				existing_pos_list.push(Object.keys(row));
+				existing_pos_list.push(Object.keys(row)[0]);
 			});
 		}
 
 		if (this.frm.doc.offline_pos_name
-			&& in_list(existing_pos_list, this.frm.doc.offline_pos_name)) {
+			&& in_list(existing_pos_list, cstr(this.frm.doc.offline_pos_name))) {
 			this.update_invoice()
-			//to retrieve and set the default payment
-			invoice_data[this.frm.doc.offline_pos_name] = this.frm.doc;
-			invoice_data[this.frm.doc.offline_pos_name].payments[0].amount = this.frm.doc.net_total
-			invoice_data[this.frm.doc.offline_pos_name].payments[0].base_amount = this.frm.doc.net_total
-
-			this.frm.doc.paid_amount = this.frm.doc.net_total
-			this.frm.doc.outstanding_amount = 0
 		} else if(!this.frm.doc.offline_pos_name) {
 			this.frm.doc.offline_pos_name = frappe.datetime.now_datetime();
 			this.frm.doc.posting_date = frappe.datetime.get_today();