chore: bump prosystem-libretro digest to a639359

This MR contains the following updates:

Package	Update	Change
prosystem-libretro	digest	4202ac5 -> a639359

---

⚠️ Warning

Some dependencies could not be looked up. Check the Dependency Dashboard for more information.

🗒Changelog
Compare revision 4202ac5bdb2ce1a21f84efc0e26d75bb5aa7e248 to a639359434cde73e6cdc651763afc587c1afb678

---

Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever MR is behind base branch, or you tick the rebase/retry checkbox.

👻 Immortal: This MR will be recreated if closed unmerged. Get config help if that's undesired.

---

• If you want to rebase/retry this MR, check this box

---

This MR has been generated by Renovate Bot.