acl2: revision bump (sbcl 2.5.6)

Signed-off-by: Rui Chen <rui@chenrui.dev>

Author: chenrui333

Formula/a/acl2.rb

@@ -4,7 +4,7 @@ class Acl2 < Formula
   url "https://github.com/acl2/acl2/archive/refs/tags/8.6.tar.gz"
   sha256 "c2d73e66422901b3cc2a6f5a9ab50f5f3b1b4060cf9dc9148d076f3a8b957cf9"
   license "BSD-3-Clause"
-  revision 8
+  revision 9
 
   livecheck do
     url :stable