adding version 20 for clang and clang++

Author: nishant-sachdeva

Manylinux2014_Compliant_Source/pkg/build.sh

@@ -1,8 +1,8 @@
 #!/bin/bash
 
 set -eu
-export CXX=clang++
-export CC=clang
+export CXX=clang++-20
+export CC=clang-20
 
 rm -rf build || true
 mkdir build