fix(buffer): remove redundant const qualifier in array constructor

- Change: byte_t const (& data)[N] → byte_t (& data)[N]
- Allows non-const byte arrays to be accepted by the constructor
- Fixes defect discovered by TEST_F(BufferTest, ConstructorFromByteArray)
- The const qualifier on array elements was too restrictive
- Keep char const & c unchanged as it's correct for single char reference

include/libipc/buffer.h

@@ -21,7 +21,7 @@ public:
     buffer(void* p, std::size_t s);
 
     template <std::size_t N>
-    explicit buffer(byte_t const (& data)[N])
+    explicit buffer(byte_t (& data)[N])
         : buffer(data, sizeof(data)) {
     }
     explicit buffer(char const & c);