fix issue #72; skip some CI actions.

Author: foldl

.github/workflows/build.yml

@@ -826,6 +826,7 @@ jobs:
 
   windows-2022-cmake-cuda:
     runs-on: windows-2022
+    if: false
 
     strategy:
       matrix:

src/models.cpp

@@ -629,6 +629,7 @@ namespace chatllm
     public:
         static const int ABORT = -1;
         Sampler() : penalty() {}
+        virtual ~Sampler() = default;
 
         Sampler(const GenerationConfig &gen_config)
             : penalty(gen_config)