gc_adapter: Remove deprecated usage of = in lambda captures

It's deprecated in C++20 to use = to capture the this pointer.

Instead, we can simply pass this as an argument to the thread
constructor.

src/input_common/gcadapter/gc_adapter.cpp

@@ -198,7 +198,7 @@ void Adapter::StartScanThread() {
     }
 
     detect_thread_running = true;
-    detect_thread = std::thread([=] { ScanThreadFunc(); });
+    detect_thread = std::thread(&Adapter::ScanThreadFunc, this);
 }
 
 void Adapter::StopScanThread() {