mirage/mirage: PR #1533: Consolidate mirage bootvar

@2026b03

Stages:

• 🟡 x86_64-debian-10-4.13
• ✔️ arm64-debian-10-4.13 (7m06s)

History:

• 17/05/2024 13:58 🟡 @2026b03 (7m06s)
• 17/05/2024 13:43 ❌ @541ee38 (5m24s)
• 17/05/2024 13:30 ❌ @69ef9e7 (10m39s)
• 17/05/2024 13:07 ❌ @f2067d3 (6m39s)
• 09/05/2024 19:03 ❌ @07b65c3 (3m08s)
• 09/05/2024 18:34 ❌ @cc63ae0 (2m11s)