ipatests: Bump required Pytest

Ipatests utilize the 'timeout' arg for 'testdir.run()', which is
available since Pytest 3.9.1 [0]

[0]: https://github.com/pytest-dev/pytest/issues/4073
Fixes: https://pagure.io/freeipa/issue/8101

Signed-off-by: Stanislav Levin <slev@altlinux.org>
Reviewed-By: Sergey Orlov <sorlov@redhat.com>

freeipa.spec.in

@@ -744,7 +744,7 @@ Requires: ldns-utils
 Requires: python3-coverage
 Requires: python3-cryptography >= 1.6
 Requires: python3-polib
-Requires: python3-pytest >= 2.6
+Requires: python3-pytest >= 3.9.1
 Requires: python3-pytest-multihost >= 0.5
 Requires: python3-pytest-sourceorder
 Requires: python3-sssdconfig >= %{sssd_version}