Should we update submodules with --recursive?

[alanz]

As far as I know none of our dependencies need a recursive clone, and some of them bring in copies of submodules we already provide ourselves, which are used when building the package in standalone fashion.

So things will go faster and probably still work if we do not do the recursive update.

[samuelpilz]

Will test!

[nponeccop]

See #1256

[samuelpilz]

closed by #1221