add python3-pip to the installer for Ubuntu

install_mp.bash

@@ -96,6 +96,7 @@ ubuntu)
   sudo apt install libc6-dev-i386
   sudo apt install csh
   sudo apt install git
+  sudo apt install python3-pip
   pip3 install --upgrade pip
   pip3 install PySide6
   pip3 install pyspellchecker