Remove single node serial upgrade lanes (#69176)

I noticed e2e-metal-ovn-single-node-rt-upgrade-serial doesn't actually
run any serial tests, we don't have any serial upgrade jobs.  That might
be a gap in our coverage, but e2e-metal-ovn-single-node-rt-upgrade-serial ends up running parallel
(upgrade_conformance in the bash script is hardcoded to parallel).

Author: stbenjam

ci-operator/config/openshift/release/openshift-release-master__nightly-4.17.yaml

@@ -158,18 +158,6 @@ tests:
       - observers-resource-watch
     workflow: openshift-upgrade-aws-single-node-realtime
   timeout: 5h0m0s
-- as: e2e-metal-ovn-single-node-rt-upgrade-serial
-  cron: 30 22 26 1 *
-  steps:
-    cluster_profile: aws
-    env:
-      SINGLE_NODE_AWS_INSTANCE_TYPE: c7i.metal-24xl
-      TEST_SUITE: openshift/conformance/serial
-    observers:
-      enable:
-      - observers-resource-watch
-    workflow: openshift-upgrade-aws-single-node-realtime
-  timeout: 5h0m0s
 - as: e2e-aws-ovn-single-node-techpreview-serial
   cron: 37 13 27 7 *
   steps:

ci-operator/config/openshift/release/openshift-release-master__nightly-4.18.yaml

@@ -170,18 +170,6 @@ tests:
       - observers-resource-watch
     workflow: openshift-upgrade-aws-single-node-realtime
   timeout: 5h0m0s
-- as: e2e-metal-ovn-single-node-rt-upgrade-serial
-  cron: 8 6 15 3 *
-  steps:
-    cluster_profile: aws
-    env:
-      SINGLE_NODE_AWS_INSTANCE_TYPE: c7i.metal-24xl
-      TEST_SUITE: openshift/conformance/serial
-    observers:
-      enable:
-      - observers-resource-watch
-    workflow: openshift-upgrade-aws-single-node-realtime
-  timeout: 5h0m0s
 - as: e2e-aws-ovn-single-node-techpreview-serial
   cron: 26 19 21 9 *
   steps:

ci-operator/config/openshift/release/openshift-release-master__nightly-4.19.yaml

@@ -174,18 +174,6 @@ tests:
       - observers-resource-watch
     workflow: openshift-upgrade-aws-single-node-realtime
   timeout: 5h0m0s
-- as: e2e-metal-ovn-single-node-rt-upgrade-serial
-  interval: 168h
-  steps:
-    cluster_profile: aws
-    env:
-      SINGLE_NODE_AWS_INSTANCE_TYPE: c7i.metal-24xl
-      TEST_SUITE: openshift/conformance/serial
-    observers:
-      enable:
-      - observers-resource-watch
-    workflow: openshift-upgrade-aws-single-node-realtime
-  timeout: 5h0m0s
 - as: e2e-aws-ovn-single-node-techpreview-serial
   interval: 168h
   steps:

ci-operator/config/openshift/release/openshift-release-master__nightly-4.20.yaml

@@ -178,18 +178,6 @@ tests:
       - observers-resource-watch
     workflow: openshift-upgrade-aws-single-node-realtime
   timeout: 5h0m0s
-- as: e2e-metal-ovn-single-node-rt-upgrade-serial
-  interval: 168h
-  steps:
-    cluster_profile: aws
-    env:
-      SINGLE_NODE_AWS_INSTANCE_TYPE: c7i.metal-24xl
-      TEST_SUITE: openshift/conformance/serial
-    observers:
-      enable:
-      - observers-resource-watch
-    workflow: openshift-upgrade-aws-single-node-realtime
-  timeout: 5h0m0s
 - as: e2e-aws-ovn-single-node-techpreview-serial
   interval: 168h
   steps:

ci-operator/config/openshift/release/openshift-release-master__nightly-4.21.yaml

@@ -178,18 +178,6 @@ tests:
       - observers-resource-watch
     workflow: openshift-upgrade-aws-single-node-realtime
   timeout: 5h0m0s
-- as: e2e-metal-ovn-single-node-rt-upgrade-serial
-  interval: 168h
-  steps:
-    cluster_profile: aws
-    env:
-      SINGLE_NODE_AWS_INSTANCE_TYPE: c7i.metal-24xl
-      TEST_SUITE: openshift/conformance/serial
-    observers:
-      enable:
-      - observers-resource-watch
-    workflow: openshift-upgrade-aws-single-node-realtime
-  timeout: 5h0m0s
 - as: e2e-aws-ovn-single-node-techpreview-serial
   interval: 168h
   steps: