bun-canary: Download from unique artifact url

[chawyehsu]

Prevent https://github.com/ScoopInstaller/Versions/issues?q=bun-canary from occuring

NOTE: It is impossible to download GHA artifacts without using GH auth token or the https://nightly.link/ service.

• [x] I have read the Contributing Guide.

[github-actions[bot]]

All changes look good.

Wait for review from human collaborators.

bun-canary

• [x] Description
• [x] License
• [x] Hashes
• [x] Checkver
• [x] Autoupdate