test(google-auth): Update constraints for Python 3.10 lower bounds and drop 3.8/3.9

Author: chalmerlowe

packages/google-auth/testing/constraints-3.10.txt

@@ -1 +1,13 @@
-urllib3<2.0.0
+# This constraints file is used to check that lower bounds
+# are correct in setup.py
+# List *all* library dependencies and extras in this file.
+# Pin the version to the lower bound.
+#
+# e.g., if setup.py has "foo >= 1.14.0, < 2.0.0dev",
+# Then this file should have foo==1.14.0
+pyasn1-modules==0.2.1
+setuptools==40.3.0
+cryptography==38.0.3
+aiohttp==3.6.2
+requests==2.20.0
+pyjwt==2.0