build: fix legacy OpenWrt package releases

agent/go/cmd/rmm-agent/main.go

@@ -23,7 +23,7 @@ import (
 	"time"
 )
 
-const agentVersion = "0.6.2"
+const agentVersion = "0.6.3"
 
 type agentRuntimeHealth struct {
 	StartedAt            time.Time

agent/go/cmd/rmm-agent/main_test.go

@@ -9,7 +9,7 @@ import (
 )
 
 func TestAgentVersionIsStable(t *testing.T) {
-	if agentVersion != "0.6.2" {
+	if agentVersion != "0.6.3" {
 		t.Fatalf("unexpected agent version %q", agentVersion)
 	}
 }