Partial/Sparse checkout GitHub workflow

uses: actions/checkout@v3
with:
sparse-checkout: 'client'
sparse-checkout-cone-mode: false
# This step is needed because expo-github-action does not support paths.
# Therefore all mobile app assets should be moved to the project root.
- name: Move mobile app files to root
run: |
ls -lah
shopt -s dotglob
mv client/* .
rm -rf client
ls -lah