Revert "Add skill approval event/response (#12633)" (#12811)

This reverts commit https://github.com/openai/codex/pull/12633. We no
longer need this PR, because we favor sending normal exec command
approval server request with `additional_permissions` of skill
permissions instead

codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.schemas.json

@@ -3052,30 +3052,6 @@
           "title": "DynamicToolCallResponseEventMsg",
           "type": "object"
         },
-        {
-          "properties": {
-            "item_id": {
-              "type": "string"
-            },
-            "skill_name": {
-              "type": "string"
-            },
-            "type": {
-              "enum": [
-                "skill_request_approval"
-              ],
-              "title": "SkillRequestApprovalEventMsgType",
-              "type": "string"
-            }
-          },
-          "required": [
-            "item_id",
-            "skill_name",
-            "type"
-          ],
-          "title": "SkillRequestApprovalEventMsg",
-          "type": "object"
-        },
         {
           "properties": {
             "id": {
@@ -6732,30 +6708,6 @@
           "title": "Item/tool/requestUserInputRequest",
           "type": "object"
         },
-        {
-          "properties": {
-            "id": {
-              "$ref": "#/definitions/RequestId"
-            },
-            "method": {
-              "enum": [
-                "skill/requestApproval"
-              ],
-              "title": "Skill/requestApprovalRequestMethod",
-              "type": "string"
-            },
-            "params": {
-              "$ref": "#/definitions/SkillRequestApprovalParams"
-            }
-          },
-          "required": [
-            "id",
-            "method",
-            "params"
-          ],
-          "title": "Skill/requestApprovalRequest",
-          "type": "object"
-        },
         {
           "description": "Execute a dynamic tool call on the client.",
           "properties": {
@@ -6877,43 +6829,6 @@
       ],
       "type": "object"
     },
-    "SkillApprovalDecision": {
-      "enum": [
-        "approve",
-        "decline"
-      ],
-      "type": "string"
-    },
-    "SkillRequestApprovalParams": {
-      "$schema": "http://json-schema.org/draft-07/schema#",
-      "properties": {
-        "itemId": {
-          "type": "string"
-        },
-        "skillName": {
-          "type": "string"
-        }
-      },
-      "required": [
-        "itemId",
-        "skillName"
-      ],
-      "title": "SkillRequestApprovalParams",
-      "type": "object"
-    },
-    "SkillRequestApprovalResponse": {
-      "$schema": "http://json-schema.org/draft-07/schema#",
-      "properties": {
-        "decision": {
-          "$ref": "#/definitions/SkillApprovalDecision"
-        }
-      },
-      "required": [
-        "decision"
-      ],
-      "title": "SkillRequestApprovalResponse",
-      "type": "object"
-    },
     "StepStatus": {
       "enum": [
         "pending",