COMPATIBILITY: new mocpy release has cdshealpix as optional dependency breaking CI here

[bsipocz]

The side effect of making the mandatory dependency optional is that it's not declared for astroquery any more. We should just be more specific here and require mocpy[plots] from now on (though that may not work for the oldestdeps job

cc @ManonMarchand

[ManonMarchand]

It shouldn't be mandatory if there are no plots in the ci. I'll do a patch today, sorry for that and thanks for catching this up.
I'll have to add a run without the optional dependencies in my own ci.

[ManonMarchand]

It should be fixed by MOCPy's version 0.19.1 ?

[bsipocz]

It should be fixed by MOCPy's version 0.19.1 ?

It's up to you if you think it's a fix in mocpy or if we just add an additional optional dependency here.