treewide: remove unnecessary types and conversions

Change-Id: Ifcaa9ceeec243b3646c9b6e0a6fad7ef2db8fd90
Reviewed-on: https://review.monogon.dev/c/monogon/+/2954
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
Tested-by: Jenkins CI
diff --git a/cloud/agent/agent.go b/cloud/agent/agent.go
index 6432586..2805f42 100644
--- a/cloud/agent/agent.go
+++ b/cloud/agent/agent.go
@@ -78,7 +78,7 @@
 	supervisor.Run(ctx, "networking", networkSvc.Run)
 	l.Info("Started networking")
 
-	ephemeralCert, err := newEphemeralCert(ed25519.PrivateKey(agentInit.PrivateKey))
+	ephemeralCert, err := newEphemeralCert(agentInit.PrivateKey)
 	if err != nil {
 		return fmt.Errorf("could not generate ephemeral credentials: %w", err)
 	}