ci(renovate): silence github.com rate limit + skip internal workflow ref

Wire an optional read-only GITHUB_COM_TOKEN so Renovate can reach
api.github.com (changelogs + actions/checkout-style updates) without
rate limiting, and disable management of the internal Gitea reusable
workflow `played/workflows` (it's a @main ref, not a github.com action).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

README.md

@@ -54,6 +54,7 @@ Self-hosted [Renovate](https://docs.renovatebot.com) that keeps dependencies ali
 
 1. Create a Gitea PAT — a dedicated `renovate` bot user is cleanest — with scopes `read:user`, `write:repository`, `write:issue`. Add it as the `RENOVATE_TOKEN` Actions secret (org-level, or on this repo).
 2. Make sure the existing `NPMRC` secret (registry + `@played` auth) is visible to this repo's Actions run (org-level recommended) — Renovate uses it to look up `@played/*` versions.
+   - *Optional but recommended:* add `RENOVATE_GITHUB_COM_TOKEN` — a **read-only** github.com PAT (no scopes). It stops `api.github.com` rate-limit warnings and enables changelogs + updates for the github.com actions in `deploy.yml` (`actions/checkout`, `appleboy/ssh-action`, …).
 3. Push, then run the workflow once (**Run workflow**). Renovate opens a "Configure Renovate" onboarding PR in each target repo that does `extends: ["local>played/workflows:renovate-config"]`; merge them to go live.
 
 ### Target repos