Retire poseidon from sig-scheduling

Related:
  - kubernetes/org#3262

Signed-off-by: Arnaud Meukam <[email protected]>

Author: ameukam

sig-scheduling/README.md

@@ -80,9 +80,6 @@ The following [subprojects][subproject-definition] are owned by sig-scheduling:
 ### kueue
 - **Owners:**
   - [kubernetes-sigs/kueue](https://github.com/kubernetes-sigs/kueue/blob/main/OWNERS)
-### poseidon
-- **Owners:**
-  - [kubernetes-sigs/poseidon](https://github.com/kubernetes-sigs/poseidon/blob/master/OWNERS)
 ### scheduler
 - **Owners:**
   - [kubernetes/kubernetes/cmd/kube-scheduler](https://github.com/kubernetes/kubernetes/blob/master/cmd/kube-scheduler/OWNERS)

sigs.yaml

@@ -2356,9 +2356,6 @@ sigs:
   - name: kueue
     owners:
     - https://raw.githubusercontent.com/kubernetes-sigs/kueue/main/OWNERS
-  - name: poseidon
-    owners:
-    - https://raw.githubusercontent.com/kubernetes-sigs/poseidon/master/OWNERS
   - name: scheduler
     owners:
     - https://raw.githubusercontent.com/kubernetes/kubernetes/master/cmd/kube-scheduler/OWNERS