mirage/mirage: PR #1524: functoria: Constraint the start function to 'unit Lwt.t'

@e89c770

Stages:

• ❌ x86_64-debian-10-4.13 (11m09s)
• ❌ arm64-debian-10-4.13 (6m08s)

History:

• 01/05/2024 14:37 ✔️ @2f9ed65 (14m16s)
• 26/04/2024 21:18 ❌ @c048550 (58m31s)
• 26/04/2024 20:05 ❌ @7fee732 (7m12s)
• 26/04/2024 11:54 ❌ @60d5a6f (12m54s)
• 26/04/2024 10:49 ❌ @e4d5a5c (6m12s)
• 26/04/2024 09:56 ❌ @e89c770 (26m27s)