Sync keys from GitHub

curl --request POST \
  --url https://cloud-api.phala.com/api/v1/user/ssh-keys/github-sync

{
  "synced_count": 123,
  "keys_added": 123,
  "keys_updated": 123,
  "keys_removed": 123,
  "errors": [
    "<string>"
  ]
}