The page specifies the price is hourly and doesn't seem to list that restriction. Could you please link to where it is specified?
Edit: I don't think you're right. I've checked the Scaleway console and it appears the minimum unit of billing for this is one hour. I'd check, but they're out of stock.
Second edit: I missed the part where it says 24 hour minimum period on the instance setup page:
"As required by Apple License, you must keep this instance at least 24 hours. You will be able to delete it only after 24 hours."
Here[1] is the license for BigSur. The relevant section is 3.A.(ii). This clause was added for BigSur so I _think_ that if you're leasing a VPS with macOS Catalina or older you can legally rent it for less than 24 hours.
Edit: It seems that before BigSur the legallity of subleasing macOS was a "gray area". I guess as long as it doesn't hurt Apple they didn't come after you.
Edit: I don't think you're right. I've checked the Scaleway console and it appears the minimum unit of billing for this is one hour. I'd check, but they're out of stock.
Second edit: I missed the part where it says 24 hour minimum period on the instance setup page:
"As required by Apple License, you must keep this instance at least 24 hours. You will be able to delete it only after 24 hours."