ubuntu_setup: fix No module apt_pkg error when setting up (#32526)

* no apt_pkg fix

* check arch

* fix if

* cleanup

* reorder

* increase shm size for selfdrive tests

* add comment explaining reinstall

* refine
old-commit-hash: f4322666c6adc4dd2da569f483f6e108f18fe32a

tools/install_python_dependencies.sh

@@ -15,7 +15,10 @@ export MAKEFLAGS="-j$(nproc)"
 
 
 echo "update pip"
-if [ ! -z "\$VIRTUAL_ENV_ROOT" ] || [ ! -z "$INSTALL_DEADSNAKES_PPA" ] ; then
+if [ ! -z "$VIRTUAL_ENV_ROOT" ] || [ ! -z "$INSTALL_DEADSNAKES_PPA" ] ; then
+  if [ -z "$VIRTUAL_ENV_ROOT" ]; then
+    export VIRTUAL_ENV_ROOT="venv"
+  fi
   python3 -m venv --system-site-packages $VIRTUAL_ENV_ROOT
   source $VIRTUAL_ENV_ROOT/bin/activate
 fi

tools/install_ubuntu_dependencies.sh

@@ -113,11 +113,13 @@ function install_deadsnakes_ppa(){
     echo ""
     if [[ $REPLY =~ ^[Yy]$ ]]; then
       INSTALL_DEADSNAKES_PPA="yes"
-      export VIRTUAL_ENV_ROOT=".venv"
     fi
   fi
   if [[ "$INSTALL_DEADSNAKES_PPA" == "yes" ]]; then
-    $SUDO apt-get install software-properties-common -y --no-install-recommends
+    # The reinstall ensures that apt_pkg.cpython-35m-x86_64-linux-gnu.so exists
+    # by reinstalling python3-minimal since it's not present in /usr/lib/python3/dist-packages.
+    $SUDO apt install -y --no-install-recommends --reinstall python3-minimal
+    $SUDO apt-get install -y --no-install-recommends python3-apt software-properties-common
     $SUDO add-apt-repository ppa:deadsnakes/ppa
     $SUDO apt-get install -y --no-install-recommends \
       python3.11-dev \