Misc type annotations

Extracted from #1272

ipykernel/kernelapp.py

@@ -54,6 +54,7 @@
 from .ipkernel import IPythonKernel
 from .parentpoller import ParentPollerUnix, ParentPollerWindows
 from .shellchannel import ShellChannelThread
+from .thread import BaseThread
 from .zmqshell import ZMQInteractiveShell
 
 # -----------------------------------------------------------------------------
@@ -142,9 +143,10 @@ class IPKernelApp(BaseIPythonApplication, InteractiveShellApp, ConnectionFileMix
     debug_shell_socket = Any()
     stdin_socket = Any()
     iopub_socket = Any()
-    iopub_thread = Any()
-    control_thread = Any()
-    shell_channel_thread = Any()
+
+    iopub_thread: BaseThread
+    control_thread: BaseThread
+    shell_channel_thread: BaseThread
 
     _ports = Dict()
 

pyproject.toml

@@ -276,6 +276,8 @@ ignore = [
   "G002",
   # `open()` should be replaced by `Path.open()`
   "PTH123",
+  # use `X | Y` for type annotations, this does not works for dynamic getting type hints on older python
+  "UP007",
 ]
 unfixable = [
   # Don't touch print statements