Followup fbc7ecb: make mediawiki.mobile depend on core.mobile, not core

Because we also need MobileContext in order to be able to extend it.

I hate our disorganized set of modules. Yes, I said that yesterday too.

Bug: 72282
Change-Id: I7276fc6ee82805f39c47864101ce495a561caa66
Merge "Followup fbc7ecb: make mediawiki.mobile depend on core.mobile, not core"