[unmaintained only] Drop sdk job

Since [1] some projects like octavia transitioned
to eol and their unmaintained branches got removed.
with it sdk job started failing, removing this job
from our periodic queue.

[1] https://review.opendev.org/q/topic:%22eom-to-eol%22

Change-Id: I9333358bd20e9314ea39db021ebb7641dc33aa45
(cherry picked from commit c9d12e1)
Conflicts:
	zuul.d/job-templates.yaml

Author: karelyatin

zuul.d/job-templates.yaml

@@ -109,7 +109,6 @@
         - neutron-ovn-tempest-mariadb-full
         - neutron-ovn-tempest-ovs-release
         - neutron-ovn-tempest-ovs-release-ipv6-only
-        - openstacksdk-functional-devstack-networking
         - neutron-linuxbridge-tempest-plugin-scenario-nftables
         - neutron-ovs-tempest-plugin-scenario-iptables_hybrid-nftables
         - devstack-enforce-scope