cleanup kernelspec loading...
cleanup kernelspec loading
- kernel_selector.set_kernel validates selection and triggers 'spec_changed.Kernel'. It does not start the session anymore.
- notebook calls kernel_selector.set_kernel when:
- kernelspec is in notebook metadata
- session is loaded (e.g. no kernelspec metadata)
- notebook starts session, loads metadata on spec_changed.kernel
The only case where starting the session is not triggered by spec_changed is on notebook load with no kernel metadata
