chore: Fix warnings for Rust 1.89 (#32378)

Closes #ISSUE

Release Notes:

- N/A

crates/channel/src/channel_store.rs

@@ -111,7 +111,7 @@ pub struct ChannelMembership {
     pub role: proto::ChannelRole,
 }
 impl ChannelMembership {
-    pub fn sort_key(&self) -> MembershipSortKey {
+    pub fn sort_key(&self) -> MembershipSortKey<'_> {
         MembershipSortKey {
             role_order: match self.role {
                 proto::ChannelRole::Admin => 0,

crates/channel/src/channel_store/channel_index.rs

@@ -32,7 +32,7 @@ impl ChannelIndex {
             .retain(|channel_id| !channels.contains(channel_id));
     }
 
-    pub fn bulk_insert(&mut self) -> ChannelPathsInsertGuard {
+    pub fn bulk_insert(&mut self) -> ChannelPathsInsertGuard<'_> {
         ChannelPathsInsertGuard {
             channels_ordered: &mut self.channels_ordered,
             channels_by_id: &mut self.channels_by_id,