Revert "buildClan: Add automatic inventory import directory"

This reverts commit 850eabb98c.

This introduces the name "inventory module" whereas we already use the
term clan modules everywhere else. I don't don't too many confusing
termologies in the codebase. Let's discuss this before adding it back.

lib/build-clan/default.nix

@@ -35,6 +35,5 @@ eval {
     rest
     # implementation
     ./module.nix
-    ./imports.nix
   ];
 }