Revert "UniStore: Add folder to the SQL backend" (#95966)

Revert "UniStore: Add folder to the SQL backend (#95671)"

This reverts commit f075662696.

pkg/storage/unified/sql/data/resource_insert.sql

@@ -6,7 +6,6 @@ INSERT INTO {{ .Ident "resource" }}
         {{ .Ident "resource" }},
         {{ .Ident "namespace" }},
         {{ .Ident "name" }},
-        {{ .Ident "folder" }},
 
         {{ .Ident "previous_resource_version" }},
         {{ .Ident "value" }},
@@ -18,7 +17,6 @@ INSERT INTO {{ .Ident "resource" }}
         {{ .Arg .WriteEvent.Key.Resource }},
         {{ .Arg .WriteEvent.Key.Namespace }},
         {{ .Arg .WriteEvent.Key.Name }},
-        {{ .Arg .Folder }},
 
         {{ .Arg .WriteEvent.PreviousRV }},
         {{ .Arg .WriteEvent.Value }},