fix: Remove rename related code from Serial No (#22627)

diff --git a/erpnext/stock/doctype/serial_no/serial_no.py b/erpnext/stock/doctype/serial_no/serial_no.py
index f3514c7..90f0f58 100644
--- a/erpnext/stock/doctype/serial_no/serial_no.py
+++ b/erpnext/stock/doctype/serial_no/serial_no.py
@@ -190,23 +190,6 @@
 		if sle_exists:
 			frappe.throw(_("Cannot delete Serial No {0}, as it is used in stock transactions").format(self.name))
 
-	def before_rename(self, old, new, merge=False):
-		if merge:
-			frappe.throw(_("Sorry, Serial Nos cannot be merged"))
-
-	def after_rename(self, old, new, merge=False):
-		"""rename serial_no text fields"""
-		for dt in frappe.db.sql("""select parent from tabDocField
-			where fieldname='serial_no' and fieldtype in ('Text', 'Small Text')"""):
-
-			for item in frappe.db.sql("""select name, serial_no from `tab%s`
-				where serial_no like %s""" % (dt[0], frappe.db.escape('%' + old + '%'))):
-
-				serial_nos = map(lambda i: new if i.upper()==old.upper() else i, item[1].split('\n'))
-				frappe.db.sql("""update `tab%s` set serial_no = %s
-					where name=%s""" % (dt[0], '%s', '%s'),
-					('\n'.join(list(serial_nos)), item[0]))
-
 	def update_serial_no_reference(self, serial_no=None):
 		last_sle = self.get_last_sle(serial_no)
 		self.set_purchase_details(last_sle.get("purchase_sle"))