Sync one repo at a time

[amberin]

• ✅ I have searched for existing issues that may be the same as or related to mine.

I have started to use multiple Git repos (on my own PR branch #963). It works well, but syncing is painfully slow.

I haven't looked at the logic for the other repo types, but I believe Git syncing could be made a lot faster if we would group notebooks by repo before syncing them. This would speed up Git syncing even when using only a single repo.

Today, we loop over all notebooks, and sync them separately. (I have already moved git pushing out of this loop to save some time.)

But syncing repos separately would allow a much faster workflow for Git. There would be no need to loop over each notebook, and when there are changes, they could all go into a single commit.

For other repo types, looping over notebooks would still be possible, if necessary.

Can anyone see problems with this approach?