chore: unix/XArchUnix, use default for constructor and deconstructor, explicit constructor with no except deconstructor

src/lib/arch/unix/XArchUnix.h

@@ -13,12 +13,10 @@
 class XArchEvalUnix : public XArchEval
 {
 public:
-  XArchEvalUnix(int error) : m_error(error)
-  {
-  }
-  ~XArchEvalUnix() throw() override
+  explicit XArchEvalUnix(int error) : m_error(error)
   {
   }
+  ~XArchEvalUnix() noexcept override = default;
 
   std::string eval() const override;