Remove train and ussuri jobs

Train and Ussuri are already EOL.

Change-Id: I9b485c98f2b88a92442df0f236aa1503c9c6954f
diff --git a/zuul.d/base-nested-switch.yaml b/zuul.d/base-nested-switch.yaml
index cb3d32e..8533e07 100644
--- a/zuul.d/base-nested-switch.yaml
+++ b/zuul.d/base-nested-switch.yaml
@@ -24,7 +24,7 @@
     parent: neutron-tempest-plugin-base
     abstract: true
     branches:
-      regex: ^(unmaintained|stable/(train|ussuri|victoria|wallaby|xena|yoga|zed)).*$
+      regex: ^(unmaintained|stable/(victoria|wallaby|xena|yoga|zed)).*$
       negate: true
     # Comment nodeset and vars to switch back to non nested nodes
     nodeset: neutron-nested-virt-ubuntu-jammy
@@ -53,4 +53,4 @@
     name: neutron-tempest-plugin-base-nested-switch
     parent: neutron-tempest-plugin-base
     abstract: true
-    branches: ^(stable/(train|ussuri|victoria|wallaby|xena)).*$
+    branches: ^(stable/(victoria|wallaby|xena)).*$