chore: prepare patch releases on top of v0.51.3

Note that this does not release v0.51.4, i.e. there is no patch release of the meta crate `libp2p`.

Pull-Request: #3854.

protocols/gossipsub/CHANGELOG.md

@@ -1,4 +1,4 @@
-## 0.44.4 - unreleased
+## 0.44.4
 
 - Deprecate `metrics`, `protocol`, `subscription_filter`, `time_cache` modules to make them private. See [PR 3777].
 - Honor the `gossipsub::Config::support_floodsub` in all cases.

protocols/identify/CHANGELOG.md

@@ -1,4 +1,4 @@
-## 0.42.2 - unreleased
+## 0.42.2
 
 - Do not implicitly dial a peer upon `identify::Behaviour::push`.
   Previously, we would dial each peer in the provided list.

protocols/kad/CHANGELOG.md

@@ -1,4 +1,4 @@
-## 0.43.3 - unreleased
+## 0.43.3
 
 - Preserve existing `KeepAlive::Until` timeout instead of continuously setting new `KeepAlive::Until(Instant::now() + self.config.idle_timeout)`.
   See [PR 3801].

protocols/request-response/CHANGELOG.md

@@ -1,4 +1,4 @@
-## 0.24.1 - unreleased
+## 0.24.1
 
 - Deprecate `handler`, `codec` modules to make them private. See [PR 3847].