Revert "fix: add child item groups into the filters (#26997)" (#27266)

This reverts commit c60d5523bca0a0631555a6234a485cd7a1e3c245.
diff --git a/erpnext/selling/report/sales_partner_target_variance_based_on_item_group/item_group_wise_sales_target_variance.py b/erpnext/selling/report/sales_partner_target_variance_based_on_item_group/item_group_wise_sales_target_variance.py
index 24ca666..89cfa16 100644
--- a/erpnext/selling/report/sales_partner_target_variance_based_on_item_group/item_group_wise_sales_target_variance.py
+++ b/erpnext/selling/report/sales_partner_target_variance_based_on_item_group/item_group_wise_sales_target_variance.py
@@ -44,18 +44,6 @@
 		if d.item_group not in item_groups:
 			item_groups.append(d.item_group)
 
-	if item_groups:
-		child_items = []
-		for item_group in item_groups:
-			if frappe.db.get_value("Item Group", {"name":item_group}, "is_group"):
-				for child_item_group in frappe.get_all("Item Group", {"parent_item_group":item_group}):
-					if child_item_group['name'] not in child_items:
-						child_items.append(child_item_group['name'])
-
-		for item in child_items:
-			if item not in item_groups:
-				item_groups.append(item)
-
 	date_field = ("transaction_date"
 		if filters.get('doctype') == "Sales Order" else "posting_date")