Installer actually emits 2 non-debug logs:
WARNING Quota API is not available and therefore will skip checking them: failed to get network quota records: failed to get QuotaSets from OpenStack Network API: Resource not found
FATAL failed to fetch Master Machines: failed to load asset "Install Config": openstack platform does not have the required standard-attr-tag network extension
The first is the real problem: PSI appears to have disabled quota. Unfortunately this causes collectInfo to incorrectly shortcut  and not load network extensions, which results in the incorrectly reported network validation error.
Removing the Triaged keyword because:
* the QE automation assessment (flag qe_test_coverage) is missing
Verified in 4.11.0-0.nightly-2022-02-04-050619 on PSI.
As the quota API is not available a warning message is shown but OCP installation progresses successfully:
02-04 10:03:26.342 [INFO] Generating manifests files.....
02-04 10:03:27.716 level=warning msg=Quota API is not available and therefore will skip checking them: failed to get network quota records: failed to get QuotaSets from OpenStack Network API: Resource not found
02-04 10:03:27.716 level=info msg=Credentials loaded from file "/home/jenkins/ws/workspace/ocp-common/Flexy-install/flexy/workdir/clouds.yaml.20220204-242-1iac679"
02-04 10:03:27.972 level=info msg=Consuming Install Config from target directory
02-04 10:03:28.543 level=info msg=Manifests created in: /home/jenkins/ws/workspace/ocp-common/Flexy-install/flexy/workdir/install-dir/manifests and /home/jenkins/ws/workspace/ocp-common/Flexy-install/flexy/workdir/install-dir/openshift
02-04 10:03:35.378 [INFO] Launching 'create cluster' installation step.....
02-04 10:03:35.647 level=debug msg=OpenShift Installer 4.11.0-0.nightly-2022-02-04-050619
02-04 10:43:08.926 level=info msg=Install complete!
02-04 10:43:08.926 level=info msg=To access the cluster as the system:admin user when using 'oc', run 'export KUBECONFIG=xx'
02-04 10:43:08.926 level=info msg=Access the OpenShift web-console here: https://xxx
02-04 10:43:08.926 level=info msg=Login to the console with user: "kubeadmin", and password: "xx"
02-04 10:43:08.926 level=debug msg=Time elapsed per stage:
02-04 10:43:08.926 level=debug msg= masters: 3m22s
02-04 10:43:08.926 level=debug msg= bootstrap: 1m6s
02-04 10:43:08.926 level=debug msg=Bootstrap Complete: 10m54s
02-04 10:43:08.926 level=debug msg= API: 3m3s
02-04 10:43:08.926 level=debug msg= Bootstrap Destroy: 25s
02-04 10:43:08.926 level=debug msg= Cluster Operators: 17m47s
02-04 10:43:08.926 level=info msg=Time elapsed: 39m23s
02-04 10:43:08.926 waiting for operation up to 36000 seconds..
This doesn't require documentation as the bug was never included in a release.
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory (Important: OpenShift Container Platform 4.11.0 bug fix and security update), and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.