sdhash: disable formula (#66309)

Co-authored-by: Mitchell Blank Jr <mitch@bodyfour.com>

Formula/sdhash.rb

@@ -13,6 +13,15 @@ class Sdhash < Formula
     sha256 "3d019e14266847dcfa7fa27f69ffa4aea25cc78a2ff62c1883a2a8c74fa02116" => :sierra
   end
 
+  # This version does not build on Big Sur, and the project seems to be unmaintained overall:
+  # * The homepage says that the latest version is 3.4, but github says 4.0 is
+  # * Even the github hasn't had a commit made to it since 2013 https://github.com/sdhash/sdhash/commits/master
+  # * Seems to have Python 2 dependencies.  There is an open PR on the project to
+  #   make it compatible with Python 3.7, but so far it hasn't been merged
+  # If there is ever a post-4.0 release on github this formula might be resurrected
+  # but for now it seems dead.
+  disable! because: :does_not_build
+
   depends_on "openssl@1.1"
 
   def install