fix(lib): doom-files-in's :map causing type errors

This regression was introduced in 10d00b7cc4, causing
"wrong-type-argument: stringp (X . Y)" errors. It is triggered when
doom-files-in is used with a non-nil :map on a nested directory
tree (like our module tree).

Fix: #6370
Amend: 10d00b7cc4

core/autoload/files.el

@@ -118,7 +118,8 @@ MATCH is a string regexp. Only entries that match it will be included."
                    (apply #'doom-files-in file
                           (append (list :mindepth (1- mindepth)
                                         :depth (1- depth)
-                                        :relative-to relative-to)
+                                        :relative-to relative-to
+                                        :map nil)
                                   rest)))))
             ((and (memq type '(t files))
                   (string-match-p match file)