Replace Decryptor CRTP base with a concept.

Chaos/Cipher/Block/Des/DesCrypt.hpp

@@ -281,7 +281,7 @@ public:
 
     static_assert(Chaos::Cipher::Block::Encryptor<Encryptor>);
 
-    class Decryptor : public Chaos::Cipher::Block::Decryptor<Decryptor>
+    class Decryptor
     {
     public:
         using Block = DesCrypt::Block;
@@ -327,6 +327,8 @@ public:
         Inner_::KeySchedule Schedule_;
     };
 
+    static_assert(Chaos::Cipher::Block::Decryptor<Decryptor>);
+
 private:
     using BlockHalf = uint32_t;
     using RawBlockArray = Service::SeArray<uint8_t, 8>;