[stable-only] Remove "devstack-tobiko-neutron" job

The job is failing in the periodic queue. As decided in the Neutron CI
meeting [1], this job is removed from the CI.

[1]https://meetings.opendev.org/meetings/networking/2025/networking.2025-05-06-13.00.log.html

Change-Id: I0590788179e8b3e05422bc942cb517423b555878

Author: ralonsoh

zuul.d/job-templates.yaml

@@ -68,8 +68,6 @@
         - neutron-ovn-tempest-ovs-master-centos-9-stream
         - neutron-ovs-tempest-fips
         - neutron-ovn-tempest-ovs-release-fips
-        - devstack-tobiko-neutron:
-            voting: true
         - ironic-tempest-ipa-wholedisk-bios-agent_ipmitool-tinyipa
         - openstacksdk-functional-devstack-networking
         - neutron-linuxbridge-tempest-plugin-nftables
@@ -94,8 +92,6 @@
         - neutron-ovn-tempest-ovs-master-centos-9-stream
         - neutron-ovs-tempest-fips
         - neutron-ovn-tempest-ovs-release-fips
-        - devstack-tobiko-neutron:
-            voting: true
         - ironic-tempest-ipa-wholedisk-bios-agent_ipmitool-tinyipa
         - openstacksdk-functional-devstack-networking
         - neutron-linuxbridge-tempest-plugin-scenario-nftables