[fix] removing char_array_copy from header

src/string_utils.h

@@ -96,8 +96,6 @@ void char_array_append_reversed(char_array *array, char *str);
 void char_array_append_reversed_len(char_array *array, char *str, size_t len);
 void char_array_terminate(char_array *array);
 
-char_array *char_array_copy(char_array *array);
-
 // Similar to strcat, strips NUL-byte and guarantees 0-terminated
 void char_array_cat(char_array *array, char *str);
 void char_array_cat_len(char_array *array, char *str, size_t len);