fixup! fixup! fixup! Migrate workflows to Blacksmith

Author: fhunleth

.github/workflows/ci.yml

@@ -18,6 +18,8 @@ jobs:
         include:
           - os: { name: Windows, runner: blacksmith-2vcpu-windows-2025 }
             beam: { otp: '28', elixir: '1.19' }
+            env:
+              ImageOS: win25
     steps:
       - uses: actions/checkout@v4