github: use the same synchronisation loop on every sync iteration
github: use the same synchronisation loop on every sync iteration

The only difference between the first iteration and the other ones
are how we compute the API calls to make. This needs to change
anyway at one point, as we want more control over the retry policy
and cancelation of these calls.

Signed-off-by: Thomas Gazagnaire <5f50a84c1fa3bcff146405017f36aec1a10a9e38@gazagnaire.org>

docker/datakit,docker/datakit,docker/datakit