Add API to sync registry

[vdayanand]

Now the sync API is available to non-admin, we should have an API for this

[asinghvi17]

Could I potentially trigger a registry sync from CI?

[asinghvi17]

That would really speed up our ecosystem update workflow in Dyad

[mortenpi]

We have the registry APIs in the experimental section. I think it would be fine to add this there too.

• https://help.juliahub.com/juliahub-jl/stable/reference/experimental/