app-permissions schema missing `discussions` permission

[salmanmkc]

Problem

The app-permissions schema in the OpenAPI description does not include a discussions property, even though GitHub Apps can be granted the discussions permission (read/write).

The schema currently has team_discussions but not discussions. These are different permission scopes — discussions controls access to repository Discussions (the Q&A/announcements feature), while team_discussions controls access to team discussion posts.

Impact

Downstream consumers like @octokit/openapi and actions/create-github-app-token generate their permission inputs from this schema. Because discussions is missing, users get an Unexpected input warning when setting permission-discussions in their workflows.

Short-term fix applied in actions/create-github-app-token#360, but the proper fix is here in the source schema.

Expected

Add discussions to the app-permissions component schema with:

"discussions": {
  "description": "The level of permission to grant the access token for discussions.",
  "enum": ["read", "write"],
  "type": "string"
}

[salmanmkc]

actually may be in openapi