Implement __lt__ as required for heapq.heapify.

shortfin/python/shortfin_apps/llm/components/kvcache/trie_attention_cache.py

@@ -90,6 +90,10 @@ def __eq__(self, other: object) -> bool:
         """Nodes are equal only if they are the same object."""
         return self is other
 
+    def __lt__(self, other):
+        """Sort nodes by their memory address."""
+        return id(self) < id(other)
+
 
 class TriePagedAttentionCacheAllocation(PageAllocation):
     """Represents a page allocation in the trie-based cache.