fix: dont add trailing decimal separator (#25389) (#25391)

(cherry picked from commit ddaf1d2)

Co-authored-by: Ankush Menat <ankush@frappe.io>

frappe/public/js/frappe/utils/number_format.js

@@ -66,7 +66,11 @@ function convert_old_to_new_number_format(v, old_number_format, new_number_forma
 	let old_group_regex = new RegExp(old_info.group_sep === "." ? "\\." : old_info.group_sep, "g");
 	v_before_decimal = v_before_decimal.replace(old_group_regex, new_info.group_sep);
 
-	v = v_before_decimal + new_info.decimal_str + v_after_decimal;
+	v = v_before_decimal;
+	if (v_after_decimal) {
+		v = v + new_info.decimal_str + v_after_decimal;
+	}
+
 	return v;
 }