neovim: move the debug logs to other directory

[Cedric Halbronn]

At the moment, the neovim logs are stored into the out folder:

"NVIM_NODE_LOG_FILE": "${workspaceFolder}/packages/cursorless-neovim/out/nvim_node.log",

From Pokey:

usually that contains the artifacts that should actually go into the extension. Not a showstopper tho if it's going to be a hassle to do something else; can mention in issue describing better logging approach that we already know we want

We could consider saving the logs into the temp directory.

Note that one advantage of having it into out is that it is clobbered with pnpm clean