fix: if not budget then don't validate (backport #38861) (#38865)

fix: if not budget then don't validate (#38861)

(cherry picked from commit d375164100)

Co-authored-by: rohitwaghchaure <rohitw1991@gmail.com>

erpnext/stock/doctype/material_request/material_request.py

@@ -169,7 +169,9 @@ class MaterialRequest(BuyingController):
 	def on_submit(self):
 		self.update_requested_qty_in_production_plan()
 		self.update_requested_qty()
-		if self.material_request_type == "Purchase":
+		if self.material_request_type == "Purchase" and frappe.db.exists(
+			"Budget", {"applicable_on_material_request": 1, "docstatus": 1}
+		):
 			self.validate_budget()
 
 	def before_save(self):