PEP 593: Update author email (#4892)

Author: till-varoquaux

peps/pep-0593.rst

@@ -1,6 +1,6 @@
 PEP: 593
 Title: Flexible function and variable annotations
-Author: Till Varoquaux <till@fb.com>, Konstantin Kashin <kkashin@fb.com>
+Author: Till Varoquaux <till.varoquaux@gmail.com>, Konstantin Kashin <kkashin@fb.com>
 Sponsor: Ivan Levkivskyi <levkivskyi@gmail.com>
 Discussions-To: typing-sig@python.org
 Status: Final