fix(cli): suppress coding-system prompts

Emacs can unpredictably prompt the user to "Select coding
system (default utf-8):" in some cases. The exact cause is a little
different for every user, but it can be suppressed by explicitly setting
a default language environment. This is not desirable in interactive
sessions, however.

Ref: #3042
Close: #7330
Co-authored-by: bennyip <bennyip@users.noreply.github.com>

lisp/doom-cli.el

@@ -56,6 +56,9 @@
   (require 'seq)
   (require 'map)
 
+  ;; Suppress any possible coding system prompts during CLI sessions.
+  (set-language-environment "UTF-8")
+
   ;; Load and set up our debugger first, so backtraces can be made more
   ;; presentable and logged to file.
   (doom-require 'doom-lib 'debug)