feat(core/tree): have Tree.node() raise exception instead of returnin…

…g None

src/qtile_bonsai/core/tree.py

@@ -102,14 +102,14 @@ def root(self) -> TabContainer | None:
     def is_empty(self) -> bool:
         return self.root is None
 
-    def node(self, id: int) -> Node | None:
+    def node(self, id: int) -> Node:
         """Return the node in the tree with the provided `id` or `None` if no such node
         exists.
         """
         for n in self.iter_walk():
             if n.id == id:
                 return n
-        return None
+        raise ValueError(f"There is no node with the id: {id}")
 
     def make_default_config(self) -> collections.defaultdict[int, dict[str, Any]]:
         config = collections.defaultdict(dict)