Updated py-setuptools_scm to 1.15.5.

v1.15.5
=======

* fix #167 by correctly respecting preformatted version metadata
  from PKG-INFO/EGG-INFO

v1.15.4
=======

* fix issue #164: iterate all found entry points to avoid erros when pip remakes egg-info
* enhance self-use to enable pip install from github again

v1.15.3
=======

* bring back correctly getting our version in the own sdist, finalizes #114
* fix issue #150: strip local components of tags

v1.15.2
=======

* fix issue #128: return None when a scm specific parse fails in a worktree to ease parse reuse

v1.15.1
=======

* fix issue #126: the local part of any tags is discarded
  when guessing new versions
* minor performance optimization by doing fewer git calls
  in the usual cases

(wiz)