Require jupyter_server 1.24, tornado 6.1, and traitlets 5.1

- Tornado 6.1 is required by jupyter_server 1.1+, notebook 6.2+ and jupyterlab 3+
- traitlets 5.1 is required by jupyter_server 1.16+

I think bumping to jupyter_server 1.24 should be fine, and traitlets and
tornado too.

.github/workflows/test.yaml

@@ -99,16 +99,11 @@ jobs:
           - os: ubuntu-22.04
             python-version: "3.8"
             pip-extras: classic
-            # jupyter-client and jupyter-core are transient dependencies for
-            # jupyter-server that we have to pin to avoid issues installing
-            # tornado as old as 5.1
             pip-install-constraints: >-
-              jupyter-server==1.0
-              simpervisor==1.0
-              tornado==5.1
-              traitlets==4.2.1
-              jupyter-client==7.2.0
-              jupyter-core==4.9.2
+              jupyter-server==1.24.0
+              simpervisor==1.0.0
+              tornado==6.1.0
+              traitlets==5.1.0
 
           # Workaround for excluded 3.12 test mentioned in a FIXME above
           - os: ubuntu-22.04

pyproject.toml

@@ -44,10 +44,10 @@ classifiers = [
 dependencies = [
     "aiohttp",
     "importlib_metadata >=4.8.3 ; python_version<\"3.10\"",
-    "jupyter-server >=1.0",
-    "simpervisor >=1.0",
-    "tornado >=5.1",
-    "traitlets >= 4.2.1",
+    "jupyter-server >=1.24.0",
+    "simpervisor >=1.0.0",
+    "tornado >=6.1.0",
+    "traitlets >= 5.1.0",
 ]
 
 [project.optional-dependencies]