KFLUXINFRA-3694 Simplify to FIFO scheduling for signing pipelines (#340)

Remove the konflux-signing WorkloadPriorityClass and simplify the CEL
priority expression to assign konflux-default to all pipelines. Kueue's
BestEffortFIFO strategy handles ordering by creation time, which is the
desired scheduling behavior for the signing use case (ISV-6622). The
signing-server-request resource quota remains for independent concurrency
control.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: manish-jangra

components/kueue/internal-staging/queue-config/workload-priority-class.yaml

@@ -1,13 +1,6 @@
 ---
 apiVersion: kueue.x-k8s.io/v1beta1
 kind: WorkloadPriorityClass
-metadata:
-  name: konflux-signing
-value: 950
-description: "High priority for signing pipelines rate-limited via ISV-6622"
----
-apiVersion: kueue.x-k8s.io/v1beta1
-kind: WorkloadPriorityClass
 metadata:
   name: konflux-default
 value: 400

components/kueue/internal-staging/tekton-kueue/config.yaml

@@ -2,12 +2,6 @@ queueName: pipelines-queue
 cel:
   expressions:
     - |
-        has(pipelineRun.metadata.labels) &&
-        'internal-services.appstudio.openshift.io/rate-limited' in pipelineRun.metadata.labels &&
-        pipelineRun.metadata.labels['internal-services.appstudio.openshift.io/rate-limited'] == 'true' &&
-        'internal-services.appstudio.openshift.io/rate-limiting-group' in pipelineRun.metadata.labels &&
-        pipelineRun.metadata.labels['internal-services.appstudio.openshift.io/rate-limiting-group'] == 'signing-server' ?
-        priority('konflux-signing') :
         priority('konflux-default')
 
     - |