We do not run `pexpect` based tests on Windows, but there are still cases where those tests run `import pexpect` outside of the scope where the test is skipped. By moving the import statement to a different scope, those tests can run even when `pexpect` truly isn't installed.
Tangentially related: TestSTTYBeforeAndAfter.py is using a manual `@expectedFailureAll` for windows instead of the common `@skipIfWindows`. If `pexepect` is generally expected to not be available, we should not bother running the test at all.
We need to generate events when finalizing, or we won't know that we
succeeded in stopping the process to detach/kill. Instead, we stall and
then after our 20 interrupt timeout, we kill the process (even if we
were supposed to detach) and exit.
OTOH, we have to not generate events when the Process is being
destructed because shared_from_this has already been torn down, and
using it will cause crashes.
