Remove setting explicit pool_idle_timeout since default is already 90s

Author: landonxjames

.changelog/hyper-defaults.md

@@ -4,10 +4,9 @@ applies_to:
 authors:
   - landonxjames
 references:
-  - smithy-rs#4274
+  - smithy-rs#4282
 breaking: false
 new_feature: false
 bug_fix: true
 ---
-Set the `pool_idle_timeout` for the default Hyper client to 90 seconds. This aligns with the behavior of the hyper 0.14.x client that was previously the default.
-https://github.com/smithy-lang/smithy-rs/issues/4282
+Set the `pool_timer` for the default Hyper client. This is required to allow the `pool_idle_timeout` to work. Now idle connections will be released by the pool after 90 seconds.

rust-runtime/aws-smithy-http-client/src/client.rs

@@ -195,8 +195,8 @@ impl<Any> ConnectorBuilder<Any> {
     {
         let client_builder = self.client_builder.unwrap_or_else(|| {
             let mut builder = hyper_util::client::legacy::Builder::new(TokioExecutor::new());
+            // Explicitly setting the pool_timer is required for connection timeouts to work.
             builder.pool_timer(TokioTimer::new());
-            builder.pool_idle_timeout(Duration::from_secs(90));
 
             builder
         });