Change beta_version to 8.x-beta (#8673)

* Change beta_version to 8.x-beta

* change to 8.x.x-beta
diff --git a/erpnext/hooks.py b/erpnext/hooks.py
index 5b4e687..af4dd3b 100644
--- a/erpnext/hooks.py
+++ b/erpnext/hooks.py
@@ -12,7 +12,7 @@
 app_license = "GNU General Public License (v3)"
 source_link = "https://github.com/frappe/erpnext"
 
-develop_version = '8.0.0-beta'
+develop_version = '8.x.x-beta'
 
 error_report_email = "support@erpnext.com"