chore(*): add mathlib4 synchronization comments (#18355)
Regenerated from the [port status wiki page](https://github.com/leanprover-community/mathlib/wiki/mathlib4-port-status).
Relates to the following files:
* `algebra.big_operators.fin`
* `data.finset.finsupp`
* `data.finset.functor`
* `data.finset.pointwise`
* `data.finsupp.basic`
* `data.finsupp.big_operators`
* `data.finsupp.pwo`
* `data.multiset.locally_finite`
* `data.set.pointwise.interval`
* `group_theory.subgroup.pointwise`
* `group_theory.submonoid.pointwise`
* `order.compactly_generated`
* `order.minimal`
* `order.upper_lower.basic`
* `order.well_founded_set`
* `ring_theory.subsemiring.pointwise`
* `topology.bases`
* `topology.subset_properties`
