Remove advice before before org-capture-place template

Now that nroam inserts a non read-only \n after the sections so that text can be
inserted after nroam sections at the end of the buffer, remove the extra
read-only \n so that org-capture can insert templates.

* nroam.el (nroam--handle-org-capture): Remove function and advice.
* nroam-unlinked.el (nroam-unlinked--insert-toggle-button): Do not insert a
read-only newline as it prevents org-capture from inserting the template as it
tries to delete empty lines at the end of the buffer.

nroam-unlinked.el

@@ -62,8 +62,7 @@
   "Insert a button to show unlinked references."
   (let ((beg (point)))
     (insert "[Show unlinked references]")
-    (make-text-button beg (point) 'action #'nroam-unlinked--show-references)
-    (insert "\n")))
+    (make-text-button beg (point) 'action #'nroam-unlinked--show-references)))
 
 (defun nroam-unlinked--show-references (&rest _)
   "Search for and show unlinked references."

nroam.el

@@ -56,18 +56,6 @@
 (defvar-local nroam-start-marker nil)
 (defvar-local nroam-end-marker nil)
 
-(defun nroam--handle-org-capture (&rest _)
-  "Setup the `org-capture' buffer.
-
-Nroam sections need to be pruned as they are in read-only,
-otherwise `org-capture' will fail to insert the capture
-template."
-  (when-let ((buf (org-capture-get :buffer)))
-    (with-current-buffer buf
-      (nroam--prune))))
-
-(advice-add 'org-capture-place-template :before #'nroam--handle-org-capture)
-
 (defmacro with-nroam-markers (&rest body)
   "Evaluate BODY.
 Make the region inserted by BODY read-only, and marked with