execute: skip sandbox config loading when Yolo is set

Previously loadSandboxConfig was called unconditionally, causing
failures on hosts without ~/.config/ollie/sandbox/ even when yolo
mode was enabled. Move the load inside the !Yolo branch.

pkg/tools/execute/server.go

@@ -627,9 +627,13 @@ func (e *Server) executeWithStdin(ctx context.Context, code, language string, ti
 		}
 	}
 
-	cfg, err := loadSandboxConfig(sandboxName)
-	if err != nil {
-		return "", err
+	var cfg *sandbox.Config
+	var err error
+	if !e.Yolo {
+		cfg, err = loadSandboxConfig(sandboxName)
+		if err != nil {
+			return "", err
+		}
 	}
 
 	e.wdMu.RLock()