This reverts https://github.com/openai/codex/pull/3179.
#3179 appears to introduce a regression where sourcing dotfiles causes a
bunch of activity in the title bar (and potentially slows things down?)
https://github.com/user-attachments/assets/a68f7fb3-0749-4e0e-a321-2aa6993e01da
Verified this no longer happens after backing out #3179.
Original commit changeset: 62bd0e3d9d