openblas: turn off AVX512 optimizations

The AVX512 optimization has a bug in openblas-0.3.5
and can also lead to slower code on Xeon Silver CPUs.

See https://github.com/xianyi/OpenBLAS/issues/1955
and https://github.com/xianyi/OpenBLAS/issues/2029

pkgs/development/libraries/science/math/openblas/default.nix

@@ -58,6 +58,7 @@ let
       BINARY = 64;
       TARGET = setTarget "ATHLON";
       DYNAMIC_ARCH = true;
+      NO_AVX512 = true;
       USE_OPENMP = true;
     };
   };