libkookie: fix emacs lsp-mode loading

For some reason when depending on magit the dependency "f" will be
removed from the package closure.  This breaks lsp-mode.  This fix
manually installs "f" as a depedency when installing magit.

Ideally, there should be a kookie-magit module with additional
configuration, and to make sure that I can have magit installed
without having to depend on kookie-notmuch to be installed.

infra/libkookie/overlays/kookie/emacs/kookie-notmuch/default.nix

@@ -1,4 +1,16 @@
 { buildModule, epkgs, pkgs }:
 
 with epkgs;
-(buildModule "kookie-notmuch" ./. [ magit notmuch ])
+(buildModule "kookie-notmuch" ./. [ magit notmuch
+
+                                    ## FIXME: installing "f" directly
+                                    ## here is required because it is
+                                    ## a dependency of many other
+                                    ## tools, and installing magit
+                                    ## seems to remove it from the
+                                    ## emacs closure.
+                                    ##
+                                    ## Why? I don't know.  Maybe one
+                                    ## day we will understand.
+                                    f
+                                  ])