Failure to undeclare Liveliness Subscribers

[fuzzypixelz]

Describe the bug

zenoh/zenoh/src/api/session.rs

Lines 1239 to 1243 in 502d3be

	pub(crate) fn undeclare_subscriber_inner(&self, sid: Id, kind: SubscriberKind) -> ZResult<()> {
	let mut state = zwrite!(self.state);
	if let Some(sub_state) = state
	.subscribers_mut(SubscriberKind::Subscriber)
	.remove(&sid)

Only non-Liveliness Subscribers are checked.

To reproduce

1. Declare a Liveliness Subscriber
2. Undeclare it.

System info

• ref: 502d3be

[YuanYuYuan]

Relevant issue ZettaScaleLabs/rmw_zenoh#2