do not pack tikz-uml.sty together with the paper TeX file

However, if arXiv demands it, I'll re-add it.
Revert "do not pack tikz-uml.sty together with the paper TeX file"

This reverts commit 584f18fc170e624d2bd0c16273de1f01880ea812.

Arxiv does not have tikz-uml.sty