Preferring to start wpcarros-emacs with dbus-launch

When I ran `pass show some/password`, gpg, which uses pinentry would start its
ncurses password prompt. For many this wouldn't be a problem but my current
vterm version cannot send the <return> key to ncurses, so once that prompt
appears, I cannot get rid of it without C-c and killing the shell. For a day or
more I just opened suffered through this.

Today I dug more into the issue and when I ran `pinentry --version` it warned
that it couldn't connect to DBUS. After searching for more information on this,
people with similar issues recommended starting their window managers with
`dbus-launch`. I previously started Emacs with `dbus-launch`, but only because
some i3 documentation told me to do so and I just copied them. Then I switched
to EXWM and copied that pattern over. A friend of mine uses EXWM and starts his
without calling `dbus-launch` but `exec emacs`. I mirrored this thinking that I
no longer needed `dbus-launch`. What I didn't know, however, was that this
friend was using a Nix-built Emacs (like me) except that his wrapped a native
Emacs installation while mine doesn't. His natively wrapped Emacs installation
has the proper variables set to interact with dbus and other important Linuxy
things that I don't fully understand. Since I'm using a Nix-built Emacs, some of
my variables are unset or set to different values than programs expect. This is
why when I try and start `gnome-terminal` or `terminator`, they refuse to start
and warn about many unset or incorrectly variables and not being able to bind to
sockets, etc.

This change reverts back to using `dbus-launch` until I have a better
understanding of Linux, Nix, etc.

configs/shared/.xsessionrc.shared

@@ -23,4 +23,4 @@ keynav daemonize
 
 # Startup Emacs (and EXWM). This is built by calling `make install` from within
 # ~/dotfiles/emacs.
-exec wpcarros-emacs
+dbus-launch --exit-with-session wpcarros-emacs