org-latex-export-to-latex: Do not suppress major modes in babel

* lisp/ox.el (org-export-to-file): Suppress loading major mode in the
exported text explicitly instead of doing it across the whole export
process.  This way, babel evaluation will not suffer from unexpected
behavior when no major modes are being loaded.

Reported-by: Asilata Bapat <asilata@gmail.com>
Link: https://list.orgmode.org/orgmode/87fsk5955a.fsf@gmail.com/

lisp/ox.el

@@ -6586,8 +6586,7 @@ or FILE."
   (declare (indent 2))
   (if (not (file-writable-p file)) (error "Output file not writable")
     (let ((ext-plist (org-combine-plists `(:output-file ,file) ext-plist))
-	  (encoding (or org-export-coding-system buffer-file-coding-system))
-          auto-mode-alist)
+	  (encoding (or org-export-coding-system buffer-file-coding-system)))
       (if async
           (org-export-async-start
 	      (lambda (file)
@@ -6599,14 +6598,14 @@ or FILE."
 	       (with-temp-buffer
 		 (insert output)
 		 (let ((coding-system-for-write ',encoding))
-		   (write-file ,file)))
+		   (write-region (point-min) (point-max) ,file)))
 	       (or (ignore-errors (funcall ',post-process ,file)) ,file)))
         (let ((output (org-export-as
                        backend subtreep visible-only body-only ext-plist)))
           (with-temp-buffer
             (insert output)
             (let ((coding-system-for-write encoding))
-	      (write-file file)))
+	      (write-region (point-min) (point-max) file)))
           (when (and (org-export--copy-to-kill-ring-p) (org-string-nw-p output))
             (org-kill-new output))
           ;; Get proper return value.