chore(*): add mathlib4 synchronization comments (#19135)
Regenerated from the [port status wiki page](https://github.com/leanprover-community/mathlib/wiki/mathlib4-port-status).
Relates to the following files:
* `analysis.calculus.deriv.zpow`
* `analysis.quaternion`
* `analysis.specific_limits.floor_pow`
* `category_theory.sites.closed`
* `group_theory.nilpotent`
* `measure_theory.function.l1_space`
* `measure_theory.group.prod`
* `measure_theory.integral.integrable_on`
* `measure_theory.measure.haar.basic`
* `topology.homotopy.homotopy_group`
* `topology.sheaves.local_predicate`
