The fallback case for SessionSearch when Telescope isn't installed
wasn't setting the argument to handle_autosession_command correctly

If cwd_change_handling is enabled and the session being restored
contains a terminal, we might get a "Invalid argument:
buftype=terminal". Rather than restoring the session in the callback, we
schedule the restore for the next run of the event loop.

Since cwd_change_handling now restores in vim.schedule, we have to wait
for the next event loop in the tests. `vim.wait` works but using the
async testing is probably the better way in the future:

nvim-lua/plenary.nvim#271