Remove old project search code path, bump min-supported zed version for collaboration (#18404)

Release Notes:

- N/A

crates/collab/src/rpc/connection_pool.rs

@@ -32,15 +32,7 @@ impl fmt::Display for ZedVersion {
 
 impl ZedVersion {
     pub fn can_collaborate(&self) -> bool {
-        self.0 >= SemanticVersion::new(0, 134, 0)
-    }
-
-    pub fn with_list_directory() -> ZedVersion {
-        ZedVersion(SemanticVersion::new(0, 145, 0))
-    }
-
-    pub fn with_search_candidates() -> ZedVersion {
-        ZedVersion(SemanticVersion::new(0, 151, 0))
+        self.0 >= SemanticVersion::new(0, 151, 0)
     }
 }
 
@@ -169,6 +161,16 @@ impl ConnectionPool {
         self.connected_dev_servers.get(&dev_server_id).copied()
     }
 
+    pub fn online_dev_server_connection_id(
+        &self,
+        dev_server_id: DevServerId,
+    ) -> Result<ConnectionId> {
+        match self.connected_dev_servers.get(&dev_server_id) {
+            Some(cid) => Ok(*cid),
+            None => Err(anyhow!(proto::ErrorCode::DevServerOffline)),
+        }
+    }
+
     pub fn dev_server_connection_id_supporting(
         &self,
         dev_server_id: DevServerId,