Clean up LLNDK stubs

So far we created {"", "current"} stubs for LLNDK modules. But we don't
need "current" because "" itself is a stub.

This change only removes unused LLNDK stub modules with "current"
version, which aren't used at all.

Bug: 329183083
Test: m blueprint_tests
Change-Id: Ib8e880b6d88952b489657ea1ac557a48afe562a4