`n` in `Vec.replicate` should be explicit

[Saransh-cpp]

I agree. The argument to Vec.iterate should be explicit, not implicit

Should that be the case with Vec.replicate too?

Yes, nice spot!

Turns out, Vec.replicate is comparatively a lot more involved within the codebase. Would it be better if I create a downstream PR for this (given that I have updated 15+ files till now, and there still are files left with Vec.replicate occurrences)?

Originally posted in #2051 (comment)

(creating an issue to ensure that this isn't lost between PRs and reviews)