DRA: remove "classic DRA"

This removes the DRAControlPlaneController feature gate, the fields controlled
by it (claim.spec.controller, claim.status.deallocationRequested,
claim.status.allocation.controller, class.spec.suitableNodes), the
PodSchedulingContext type, and all code related to the feature.

The feature gets removed because there is no path towards beta and GA and DRA
with "structured parameters" should be able to replace it.

Author: pohly

api/discovery/aggregated_v2.json

@@ -1966,41 +1966,6 @@
                 "watch"
               ]
             },
-            {
-              "resource": "podschedulingcontexts",
-              "responseKind": {
-                "group": "",
-                "kind": "PodSchedulingContext",
-                "version": ""
-              },
-              "scope": "Namespaced",
-              "singularResource": "podschedulingcontext",
-              "subresources": [
-                {
-                  "responseKind": {
-                    "group": "",
-                    "kind": "PodSchedulingContext",
-                    "version": ""
-                  },
-                  "subresource": "status",
-                  "verbs": [
-                    "get",
-                    "patch",
-                    "update"
-                  ]
-                }
-              ],
-              "verbs": [
-                "create",
-                "delete",
-                "deletecollection",
-                "get",
-                "list",
-                "patch",
-                "update",
-                "watch"
-              ]
-            },
             {
               "resource": "resourceclaims",
               "responseKind": {

api/discovery/apis__resource.k8s.io__v1alpha3.json

@@ -20,34 +20,6 @@
         "watch"
       ]
     },
-    {
-      "kind": "PodSchedulingContext",
-      "name": "podschedulingcontexts",
-      "namespaced": true,
-      "singularName": "podschedulingcontext",
-      "storageVersionHash": "SkSsa067T7g=",
-      "verbs": [
-        "create",
-        "delete",
-        "deletecollection",
-        "get",
-        "list",
-        "patch",
-        "update",
-        "watch"
-      ]
-    },
-    {
-      "kind": "PodSchedulingContext",
-      "name": "podschedulingcontexts/status",
-      "namespaced": true,
-      "singularName": "",
-      "verbs": [
-        "get",
-        "patch",
-        "update"
-      ]
-    },
     {
       "kind": "ResourceClaim",
       "name": "resourceclaims",