message: Slight updates to make the qns runner more robust
diff: set -e
  +INTEROP_DIR=target/quic-interop-runner
  +
  # Setup the s2n-quic docker image
  sudo docker build . --file qns/Dockerfile.build --tag awslabs/s2n-quic-qns
  -if [ ! -d target/quic-interop-runner ]; then
  - git clone https://github.com/marten-seemann/quic-interop-runner target/quic-interop-runner
  +if [ ! -d $INTEROP_DIR ]; then
  + git clone https://github.com/marten-seemann/quic-interop-runner $INTEROP_DIR
  # make sure to keep this up to date with the interop workflow
  - cd target/quic-interop-runner
  + cd $INTEROP_DIR
  git checkout 3d292c252e0c0159db93b62292abcf6b040a7060
  git apply --3way ../../.github/interop/runner.patch
  + cd ../../
  +fi
  +
  +if [ ! -d $INTEROP_DIR/.venv ]; then
  + cd $INTEROP_DIR
  python3 -m venv .venv
  source .venv/bin/activate
  pip install --upgrade pip
  @@ -37,7 +44,7 @@ case "$(uname -s)" in
  ;;
  esac
  -cd target/quic-interop-runner
  +cd $INTEROP_DIR
  source .venv/bin/activate
  pip install --upgrade -r requirements.txt
  