py-setuptools_scm: updated to 1.17.0

v1.17.0:
fix regression in git support - use a function to ensure it works in egg isntalled mode
actually fail if file finding fails in order to see broken setups instead of generating broken dists

v1.16.2:
fix regression in handling git export ignores

v1.16.1
fix regression in support for old setuptools versions

v1.16.0
drop support for eol python versions
fix missuse in surogate-escape api
add the node-and-timestamp local version sheme
respect git export ignores
avoid shlex.split on windows
fix #218 - better handling of mercurial edge-cases with tag commits being considered as the tagged commit
fix #223 - remove the dependency on the interal SetupttoolsVersion as it was removed after long-standing deprecation

(adam)