Log Message:
blosc: updated to 1.21.1

Changes from 1.21.0 to 1.21.1
=============================
* Fix pthread flag when linking on ppc64le.
* Updates in codecs (some bring important performance improvements):
  * BloscLZ updated to 2.5.1.
  * Zlib updated to 1.2.11
  * Zstd updated to 1.5.0