fix: revert coretempd service type to oneshot_async

coretempd uses syscall::call::write() for init notification, which
sends raw bytes — not an fd transfer via CallFlags::FD that the Scheme
init type expects. Changing to Scheme would cause init to block forever
in call_ro waiting for an fd that never arrives in the expected format.
The oneshot_async + resilience pattern is correct for coretempd.

config/redbear-device-services.toml

@@ -484,7 +484,7 @@ requires_weak = ["04_drivers.target"]
 
 [service]
 cmd = "/usr/bin/coretempd"
-type = { scheme = "coretemp" }
+type = "oneshot_async"
 """
 
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