feat(swarm): deprecated keep_alive_timeout from OneShotHandlerConfig

Related: #3844.
Related: #4677

Pull-Request: #4680.

swarm/CHANGELOG.md

@@ -10,6 +10,8 @@
   Individual protocols should not keep connections alive for longer than necessary.
   Users should use `swarm::Config::idle_connection_timeout` instead.
   See [PR 4656](https://github.com/libp2p/rust-libp2p/pull/4656).
+- Deprecate `keep_alive_timeout` in `OneShotHandlerConfig`.
+  See [PR 4680](https://github.com/libp2p/rust-libp2p/pull/4680).
 
 [PR 4120]: https://github.com/libp2p/rust-libp2p/pull/4120
 

swarm/src/handler/one_shot.rs

@@ -233,6 +233,9 @@ where
 #[derive(Debug)]
 pub struct OneShotHandlerConfig {
     /// Keep-alive timeout for idle connections.
+    #[deprecated(
+        note = "Set a global idle connection timeout via `SwarmBuilder::idle_connection_timeout` instead."
+    )]
     pub keep_alive_timeout: Duration,
     /// Timeout for outbound substream upgrades.
     pub outbound_substream_timeout: Duration,
@@ -241,6 +244,7 @@ pub struct OneShotHandlerConfig {
 }
 
 impl Default for OneShotHandlerConfig {
+    #[allow(deprecated)]
     fn default() -> Self {
         OneShotHandlerConfig {
             keep_alive_timeout: Duration::from_secs(10),