`@default` decorator missing on `KernelClient`

[krassowski]

Compare:

MultiKernelManager (ok):

jupyter_client/jupyter_client/multikernelmanager.py

Lines 107 to 110 in 1f36fbf

	@default("context")
	def _context_default(self) -> zmq.Context:
	self._created_context = True
	return zmq.Context()

KernelManager (ok):

jupyter_client/jupyter_client/manager.py

Lines 126 to 134 in 1f36fbf

	_created_context: Bool = Bool(False)
	# The PyZMQ Context to use for communication with the kernel.
	context: Instance = Instance(zmq.Context)
	@default("context")
	def _context_default(self) -> zmq.Context:
	self._created_context = True
	return zmq.Context()

KernelClient and AsyncKernelClient (wrong?):

jupyter_client/jupyter_client/client.py

Lines 91 to 97 in 1f36fbf

	context = Instance(zmq.Context)
	_created_context = Bool(False)
	def _context_default(self) -> zmq.Context:
	self._created_context = True
	return zmq.Context()

jupyter_client/jupyter_client/asynchronous/client.py

Lines 36 to 40 in 1f36fbf

	context = Instance(zmq.asyncio.Context) # type:ignore[arg-type]
	def _context_default(self) -> zmq.asyncio.Context:
	self._created_context = True
	return zmq.asyncio.Context()

Technically I think this is not wrong, just old way of doing things as per:
https://traitlets.readthedocs.io/en/stable/migration.html#dynamic-defaults-generation-with-decorators

The use of the magic methods _{trait}_default for dynamic default generation is not deprecated, but a new @default method decorator is added

[minrk]

Yeah, not deprecated so no real problem, but it would be fine to add it. The decorator lets it be insensitive to method name, but the reserved method name remains fully supported with no plans for deprecation.