setup: perform all pyenv setup in a single place (#23408)

* consolidate pyenv setup

* cleanup openpilot_env.sh

* undo openpilot_env.sh changes

* needed on mac

* add that back

Co-authored-by: Adeeb Shihadeh <adeebshihadeh@gmail.com>
old-commit-hash: f2f8e7b930

update_requirements.sh

@@ -4,11 +4,26 @@ set -e
 DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
 cd $DIR
 
+RC_FILE="${HOME}/.$(basename ${SHELL})rc"
+if [ "$(uname)" == "Darwin" ] && [ $SHELL == "/bin/bash" ]; then
+  RC_FILE="$HOME/.bash_profile"
+fi
+
 if ! command -v "pyenv" > /dev/null 2>&1; then
   echo "pyenv install ..."
   curl -L https://github.com/pyenv/pyenv-installer/raw/master/bin/pyenv-installer | bash
-  export PATH=$HOME/.pyenv/bin:$HOME/.pyenv/shims:$PATH
+
+  echo -e "\n. ~/.pyenvrc" >> $RC_FILE
+  cat <<EOF > "${HOME}/.pyenvrc"
+if [ -z "\$PYENV_ROOT" ]; then
+  export PATH=\$HOME/.pyenv/bin:\$HOME/.pyenv/shims:\$PATH
+  export PYENV_ROOT="\$HOME/.pyenv"
+  eval "\$(pyenv init -)"
+  eval "\$(pyenv virtualenv-init -)"
+fi
+EOF
 fi
+source $RC_FILE
 
 export MAKEFLAGS="-j$(nproc)"