setup.sh: Install libstdc++-13-dev for ubuntu-20.04

Signed-off-by: Elvis Dowson <elvis.dowson@gmail.com>

Author: edowson

setup.sh

@@ -49,7 +49,9 @@ else #linux
     #     sudo apt-get update
     # fi
     if [ "$VERSION" -eq "20" ]; then
-        sudo apt-get install -y clang-12 clang++-12 cmake libc++-dev #libc++-12-dev libc++abi-12-dev libstdc++-9-dev
+        sudo add-apt-repository ppa:ubuntu-toolchain-r/test
+        sudo apt update
+        sudo apt-get install -y clang-12 clang++-12 cmake libc++-12-dev libc++abi-12-dev libstdc++-13-dev
 
         # configure update-alternatives for clang
         sudo update-alternatives --install /usr/bin/clang++ clang++ /usr/bin/clang++-12 1000