chore: Prepare for Rust edition bump to 2024 (without autofix) (#27791)

Successor to #27779 - in this PR I've applied changes manually, without
futzing with if let lifetimes at all.

Release Notes:

- N/A

crates/recent_projects/src/ssh_connections.rs

@@ -33,7 +33,7 @@ pub struct SshSettings {
 }
 
 impl SshSettings {
-    pub fn ssh_connections(&self) -> impl Iterator<Item = SshConnection> {
+    pub fn ssh_connections(&self) -> impl Iterator<Item = SshConnection> + use<> {
         self.ssh_connections.clone().into_iter().flatten()
     }