boost-python3: Fix build on Apple silicon

Patch Boost's build system to build cleanly on Apple silicon. This is
a port of PR #59257 that fixes the main boost package.

Signed-off-by: Andreas Sandberg <andreas@sandberg.uk>

Formula/boost-python3.rb

@@ -18,6 +18,14 @@ class BoostPython3 < Formula
   depends_on "boost"
   depends_on "python@3.9"
 
+  # Fix build system issues on Apple silicon. This change has aleady
+  # been merged upstream, remove this patch once it lands in a release.
+  patch do
+    url "https://github.com/boostorg/build/commit/456be0b7ecca065fbccf380c2f51e0985e608ba0.patch?full_index=1"
+    sha256 "e7a78145452fc145ea5d6e5f61e72df7dcab3a6eebb2cade6b4cfae815687f3a"
+    directory "tools/build"
+  end
+
   def install
     # "layout" should be synchronized with boost
     args = %W[