i3: fix build with strictDeps

pkgs/applications/window-managers/i3/default.nix

···
   };
 
   nativeBuildInputs = [
-    pkg-config makeWrapper meson ninja installShellFiles
+    pkg-config makeWrapper meson ninja installShellFiles perl
     asciidoc xmlto docbook_xml_dtd_45 docbook_xsl findXMLCatalogs
   ];