[VIRT] Restart descheduler-operator before running tests (#5133)

Add descheduler_operator_reconciled fixture that restarts the
descheduler-operator deployment before creating KubeDescheduler objects.

This ensures the operator reconciles after all OpenShift operators are
installed, properly protecting all "openshift-*" namespaces from
eviction. Without this, descheduler evicts pods from openshift-cnv
namespace.

Co-Authored-By: Claude Sonnet 4.5

##### What this PR does / why we need it:
Adds a module-scoped fixture that restarts the descheduler-operator
deployment to trigger reconciliation, ensuring proper namespace
protection before running descheduler tests.

##### Which issue(s) this PR fixes:

##### Special notes for reviewer:

##### jira-ticket:
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<!-- This is an auto-generated comment: release notes by coderabbit.ai
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## Summary by CodeRabbit

* **Tests**
* Enhanced descheduler test suite with improved operator reconciliation
verification to ensure consistent test execution.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Signed-off-by: Denys Shchedrivyi <dshchedr@redhat.com>

Author: dshchedr

tests/virt/node/descheduler/conftest.py

@@ -26,7 +26,7 @@
     get_boot_time_for_multiple_vms,
     get_non_terminated_pods,
 )
-from utilities.constants import TIMEOUT_5MIN, TIMEOUT_5SEC
+from utilities.constants import TIMEOUT_5MIN, TIMEOUT_5SEC, NamespacesNames
 from utilities.infra import wait_for_pods_deletion
 from utilities.virt import wait_for_migration_finished
 
@@ -36,8 +36,28 @@
 LOCALHOST = "localhost"
 
 
+@pytest.fixture(scope="package")
+def descheduler_operator_reconciled():
+    """Restart descheduler-operator deployment to trigger reconciliation.
+
+    Workaround for the issue when descheduler is installed before other OpenShift operators.
+    After restart, the operator reconciles and adds all namespaces with prefix "openshift-"
+    to the protected list.
+    """
+    LOGGER.info("Restarting descheduler-operator deployment to trigger reconciliation")
+    deployment = Deployment(
+        name="descheduler-operator",
+        namespace=NamespacesNames.OPENSHIFT_KUBE_DESCHEDULER_OPERATOR,
+    )
+    initial_replicas = deployment.instance.spec.replicas
+    deployment.scale_replicas(replica_count=0)
+    deployment.wait_for_replicas(deployed=False)
+    deployment.scale_replicas(replica_count=initial_replicas)
+    deployment.wait_for_replicas()
+
+
 @pytest.fixture(scope="module")
-def descheduler_long_lifecycle_profile(admin_client):
+def descheduler_long_lifecycle_profile(admin_client, descheduler_operator_reconciled):
     with create_kube_descheduler(
         admin_client=admin_client,
         profiles=["LongLifecycle"],
@@ -53,6 +73,7 @@ def descheduler_long_lifecycle_profile(admin_client):
 def descheduler_kubevirt_relieve_and_migrate_profile(
     admin_client,
     schedulable_nodes,
+    descheduler_operator_reconciled,
     nodes_taints_before_descheduler_test_run,
 ):
     with create_kube_descheduler(