RBAC: Remove legacy ac from authorization middleware (#68898)

remove legacy AC fallback from RBAC middleware, and some unused auth logic

pkg/services/accesscontrol/resourcepermissions/middleware.go

@@ -1,19 +1,7 @@
 package resourcepermissions
 
 import (
-	"net/http"
-
 	contextmodel "github.com/grafana/grafana/pkg/services/contexthandler/model"
-	"github.com/grafana/grafana/pkg/web"
 )
 
-func disableMiddleware(shouldDisable bool) web.Handler {
-	return func(c *contextmodel.ReqContext) {
-		if shouldDisable {
-			c.Resp.WriteHeader(http.StatusNotFound)
-			return
-		}
-	}
-}
-
 func nopMiddleware(c *contextmodel.ReqContext) {}