Revert "Sign repodata"

This reverts commit 04194f44c8.

include/xbps.h.in

@@ -1858,18 +1858,6 @@ bool xbps_mmap_file(const char *file, void **mmf, size_t *mmflen, size_t *filele
  */
 char *xbps_file_hash(const char *file);
 
-/**
- * Returns a raw byte buffer with the sha256 hash for the data specified
- * in \a buffer of length \a len.
- *
- * @param[in] buffer Pointer to byte buffer.
- * @param[in] len Length of data in buffer
- * @return A pointer to a malloc(3)ed buffer, NULL otherwise and errno
- * is set appropiately. The pointer should be free(3)d when it's no
- * longer needed.
- */
-unsigned char *xbps_buffer_hash_raw(const char *buffer, ssize_t len);
-
 /**
  * Returns a raw byte buffer with the sha256 hash for the file specified
  * by \a file.