docs(oncall): fix withShifts usage example

grafanaplane/oncall/schedule.libsonnet

@@ -37,7 +37,7 @@ local forProvider = schedule.spec.parameters.forProvider;
               + calendar.shift.withId('secondary-' + shift.metadata.name)
               // start rotating from the second person
               + calendar.shift.withStartRotationFromUserIndex(1)
-              for shift in std.objectKeysValues(self.primary.shifts)
+              for shift in self.primary.shifts
             ]),
       |||,
       [