Fix corfu-popupinfo-mode

By default, `corfu-popupinfo-mode`'s popup window appears as a new frame rather
than a proper popup. Adding `corfu-popupinfo--show` to the list of functions to
ignore seems to fix the issue.

frames-only-mode.el

@@ -54,7 +54,7 @@ To disable completion popups entirely use the variable
   :group 'frames-only)
 
 (defcustom frames-only-mode-use-window-functions
-  (list #'calendar #'report-emacs-bug 'checkdoc-show-diagnostics 'checkdoc 'org-compile-file)
+  (list #'calendar #'report-emacs-bug 'checkdoc-show-diagnostics 'checkdoc 'org-compile-file 'corfu-popupinfo--show)
   "List of functions inside which new emacs windows should be
 created instead of frames.