Make load-env-vars a core package

Fixes a race condition where the load-env-vars package is used before it
was (or could be) installed.

core/core-packages.el

@@ -41,7 +41,8 @@
 package's name as a symbol, and whose CDR is the plist supplied to its
 `package!' declaration. Set by `doom-initialize-packages'.")
 
-(defvar doom-core-packages '(persistent-soft use-package quelpa async)
+(defvar doom-core-packages
+  '(persistent-soft use-package quelpa async load-env-vars)
   "A list of packages that must be installed (and will be auto-installed if
 missing) and shouldn't be deleted.")
 

core/core.el

@@ -450,11 +450,12 @@ to least)."
       (unless (or force-p
                   (doom-initialize-autoloads doom-package-autoload-file)
                   noninteractive)
-        (user-error "Your package autoloads are missing! Run `bin/doom refresh' to regenerate them"))))
+        (user-error "Your package autoloads are missing! Run `bin/doom refresh' to regenerate them")))
 
-  ;; Load shell environment
-  (when (file-readable-p doom-env-file)
-    (load-env-vars doom-env-file))
+    ;; Load shell environment
+    (unless noninteractive
+      (when (file-readable-p doom-env-file)
+        (load-env-vars doom-env-file))))
 
   (require 'core-lib)
   (require 'core-modules)

core/packages.el

@@ -2,7 +2,6 @@
 ;;; core/packages.el
 
 ;; core.el
-(package! load-env-vars)
 (package! dotenv-mode)
 
 ;; core-os.el