[srp-client] exclude sub-type PTR when service is being removed (#7883)
[srp-client] exclude sub-type PTR when service is being removed (#7883)

This commit updates the SRP client to not include sub-types PTR
records when the base service is being removed.
abtink/openthread,abtink/openthread,jwhui/openthread,abtink/openthread,jwhui/openthread,jwhui/openthread,openthread/openthread,openthread/openthread,srickardti/openthread,srickardti/openthread,srickardti/openthread,openthread/openthread,abtink/openthread,jwhui/openthread,srickardti/openthread,openthread/openthread