fix: Improve error message (#17747)

Change ```Allocated amount can not greater than unadjusted amount``` to ```Allocated amount cannot be greater than unadjusted amount```

```Allocated amount can not be negative``` to ```Allocated amount cannot be negative```
diff --git a/erpnext/accounts/utils.py b/erpnext/accounts/utils.py
index 7c9e9b8..96f64e8 100644
--- a/erpnext/accounts/utils.py
+++ b/erpnext/accounts/utils.py
@@ -378,9 +378,9 @@
 
 def validate_allocated_amount(args):
 	if args.get("allocated_amount") < 0:
-		throw(_("Allocated amount can not be negative"))
+		throw(_("Allocated amount cannot be negative"))
 	elif args.get("allocated_amount") > args.get("unadjusted_amount"):
-		throw(_("Allocated amount can not greater than unadjusted amount"))
+		throw(_("Allocated amount cannot be greater than unadjusted amount"))
 
 def update_reference_in_journal_entry(d, jv_obj):
 	"""