admin: Remove deprecated debugAddr (#7999)

The parameter was removed in production in IN-10874.

Followup to #7838, #7840

cmd/admin/main.go

@@ -31,9 +31,6 @@ type Config struct {
 		RAService *cmd.GRPCClientConfig
 		SAService *cmd.GRPCClientConfig
 
-		// Deprecated: DebugAddr is no longer used.
-		DebugAddr string
-
 		Features features.Config
 	}
 

test/config/admin.json

@@ -4,7 +4,6 @@
 			"dbConnectFile": "test/secrets/revoker_dburl",
 			"maxOpenConns": 1
 		},
-		"debugAddr": ":8014",
 		"tls": {
 			"caCertFile": "test/certs/ipki/minica.pem",
 			"certFile": "test/certs/ipki/admin.boulder/cert.pem",