[dxvk] Use only one extra thread for async pipeline compilation

With the benefits of asynchronous compilation being generally low and
compilation in advance not being feasible, there is no reason to create
more threads.

src/dxvk/dxvk_pipecompiler.cpp

@@ -4,9 +4,7 @@
 namespace dxvk {
   
   DxvkPipelineCompiler::DxvkPipelineCompiler() {
-    // Use ~half the CPU cores for pipeline compilation
-    const uint32_t threadCount = std::max<uint32_t>(
-      1u, std::thread::hardware_concurrency() / 2);
+    constexpr uint32_t threadCount = 1u;
     
     Logger::debug(str::format(
       "DxvkPipelineCompiler: Using ", threadCount, " workers"));