bump the jupyter_server optional dependency floor

Author: dlqqq

packages/jupyter-ai/pyproject.toml

@@ -45,7 +45,7 @@ core_default_tasks = "jupyter_ai:tasks"
 
 [project.optional-dependencies]
 test = [
-    "jupyter-server[test]>=1.6,<3",
+    "jupyter_server[test]>=2.4,<3", # v2.4 is the version floor required by jupyterlab~=4.0
     "coverage",
     "pytest",
     "pytest-asyncio",