gdm/gnome not sourcing /etc/profile if default shell isn't ash

Raising this issue for more visibility and also it most likely impacts both PmOS and Alpine

This was first reported in the PostmarketOS pmaports gitlab: https://gitlab.com/postmarketOS/pmaports/-/issues/2339

Details can be found there, but essentially, if one calls chsh and chooses /bin/bash; upon next login, the environment variables and scripts found in /etc/profile and /etc/profile.d will not run and be set. This causes, for example, firefox to be run in Xwayland rather than native Wayland because MOZ_ENABLE_WAYLAND=1 is one of those scripts in /etc/profile.d