ecdsa 0.19.1

New API:

• der.remove_implicit and der.encode_implicit for decoding and
  encoding DER IMPLICIT values with custom tag values and arbitrary
  classes

Bug fixes:

• Minor fixes around arithmetic with curves that have non-prime order
  (useful for experimentation, not practical deployments)
• Fix arithmetic to work with curves that have (0, 0) on the curve
• Fix canonicalization of signatures when s is just slightly
  above half of curve order

Maintenance:

• Dropped official support for Python 3.5 (again, issues with CI, support
  for Python 2.6 and Python 2.7 is unchanged)
• Officially support Python 3.12 and 3.13 (add them to CI)
• Removal of few more unnecessary six.b literals (Alexandre Detiste)
• Fix typos in warning messages