l3build: Drop cleaning of auxfiles

As we now do everything in defined 'disposable' places this is not required.


git-svn-id: http://www.latex-project.org/svnroot/experimental/trunk@5119 de43f980-851b-0410-b2f7-c40aca1f87e0
l3build: Remove auxfiles stuff from .dtx


git-svn-id: http://www.latex-project.org/svnroot/experimental/trunk@5120 de43f980-851b-0410-b2f7-c40aca1f87e0
Missing \end{macro} added


git-svn-id: http://www.latex-project.org/svnroot/experimental/trunk@5121 de43f980-851b-0410-b2f7-c40aca1f87e0
l3build: Only copy main .zip to working dir


git-svn-id: http://www.latex-project.org/svnroot/experimental/trunk@5122 de43f980-851b-0410-b2f7-c40aca1f87e0