Upgrading mathlib dependencies

Stream: mathlib4

[Michael Rothgang]

I'd like to upgrade the versions of batteries and import-graph that mathlib uses, as #20613 and #20568 use these features, respectively. Is it fine to un-pin their revisions, or should I wait until a rc2 is released? (I'm not in a particular hurry.)

[Michael Rothgang]

CC @Kim Morrison @Johan Commelin for the above question

[Kim Morrison]

@Michael Rothgang, yes, please unpin.

[Kim Morrison]

We should have a bot that is regularly complaining that it can't update these dependencies, but it has gone silent. :-(

[Eric Wieser]

When did it go silent?

[Eric Wieser]

I would guess that pinned revisions mean that the bot has nothing to say, because lake update succeeds but does nothing

[Michael Rothgang]

#20651 (still running CI passes now)