Purge Cloudflare Cache on deploy

[delphiactual]

      - name: Purge CloudFlare cache
        run: ./build/purge-cloudflare.sh
        env:
          CLOUDFLARE_KEY: ${{ secrets.CLOUDFLARE_KEY }}
          CLOUDFLARE_EMAIL: ${{ secrets.CLOUDFLARE_EMAIL }}
          APP_DOMAIN: beta.destinyitemmanager.com

we should do this for the website as well

[delphiactual]

https://github.com/marketplace/actions/cloudflare-purge-cache