Fix simple print layout to not include an additional blank page

This magic number adjustment is due to a very ugly bug in Chromium.

(cherry picked from commit 0da8932d)

CHANGELOG.rst

@@ -15,6 +15,7 @@ Fixed
 * [Docs] Certain parts of installation docs not visible
 * Nav submenu items could not be distinguished from regular ones.
 * Group GraphQL queries failed when queried by owner or member.
+* Special printouts included a blank white page at the end.
 
 `3.1.5`_ - 2023-09-02
 ---------------------

aleksis/core/templates/core/base_simple_print.html

@@ -40,7 +40,7 @@
 
       .sheet {
         width: {{ width }}mm;
-        height: {{ height|add:-1 }}.83mm;
+        height: {{ height|add:-1 }}.73mm;
       } 
     </style>
   {% endblock %}