Mark PATCH /api/v2/incidents/incident_id/attachments endpoint as deprecated (#3453)

Co-authored-by: ci.datadog-api-spec <packages@datadoghq.com>

Author: api-clients-generation-pipeline[bot]

.generator/schemas/v2/openapi.yaml

@@ -65621,6 +65621,7 @@ paths:
 
         If you have any feedback, contact [Datadog support](https://docs.datadoghq.com/help/).'
     patch:
+      deprecated: true
       description: The bulk update endpoint for creating, updating, and deleting attachments
         for a given incident.
       operationId: UpdateIncidentAttachments
@@ -65659,9 +65660,7 @@ paths:
         operator: OR
         permissions:
         - incident_write
-      x-unstable: '**Note**: This endpoint is in public beta.
-
-        If you have any feedback, contact [Datadog support](https://docs.datadoghq.com/help/).'
+      x-unstable: '**Note**: This endpoint is deprecated.'
   /api/v2/incidents/{incident_id}/impacts:
     get:
       description: Get all impacts for an incident.

api/datadogV2/api_incidents.go

@@ -3168,6 +3168,8 @@ func (r *UpdateIncidentAttachmentsOptionalParameters) WithInclude(include []Inci
 
 // UpdateIncidentAttachments Create, update, and delete incident attachments.
 // The bulk update endpoint for creating, updating, and deleting attachments for a given incident.
+//
+// Deprecated: This API is deprecated.
 func (a *IncidentsApi) UpdateIncidentAttachments(ctx _context.Context, incidentId string, body IncidentAttachmentUpdateRequest, o ...UpdateIncidentAttachmentsOptionalParameters) (IncidentAttachmentUpdateResponse, *_nethttp.Response, error) {
 	var (
 		localVarHTTPMethod  = _nethttp.MethodPatch