emacs-configuration: Use org-expiry

* user-config/emacs/.emacs.d/config.org: Use org-expiry, adding a hook so that all captured
notes get a CREATED property. Additionally, remove emacs config from agenda-files as now that
its managed with Guix its read-only and serves no purpose. Its worth noting that TODOs are no
longer tracked there anyways, and are now tracked in my notes.

user-config/emacs/.emacs.d/config.org

@@ -1859,7 +1859,7 @@ Use [[http://gnuplot.sourceforge.net/][gnuplot]] alongside org-mode to generate
 
               (setq org-agenda-files
                     (let ((agenda-dir "~/.org/roam/agenda")
-                          (agenda-files '("~/.emacs.d/config.org")))
+                          (agenda-files '()))
                       (append
                        ;; Include manually specified agenda-files
                        agenda-files
@@ -2000,6 +2000,15 @@ Use [[http://gnuplot.sourceforge.net/][gnuplot]] alongside org-mode to generate
     :after org)
 #+end_src
 
+#+begin_src emacs-lisp
+  (use-package org-expiry
+    :config (progn
+              (org-expiry-insinuate)
+              (setq org-expiry-inactive-timestamps t))
+    :after org
+    :hook ((org-capture-mode-hook org-expiry-insert-created)))
+#+end_src
+
 #+begin_src emacs-lisp
   ;; GUIX TODO: This package is not available
   ;; (use-package org-magit