builtin: improve skiplist for module autodetection
builtin: improve skiplist for module autodetection

Skips spec/ files even when there is no src/

luarocks/luarocks,tarantool/luarocks,keplerproject/luarocks,tarantool/luarocks,luarocks/luarocks,luarocks/luarocks,keplerproject/luarocks,tarantool/luarocks,keplerproject/luarocks,keplerproject/luarocks