chore(*): add mathlib4 synchronization comments (#19089)
Regenerated from the [port status wiki page](https://github.com/leanprover-community/mathlib/wiki/mathlib4-port-status).
Relates to the following files:
* `algebra.category.Group.filtered_colimits`
* `algebra.category.Module.limits`
* `algebra.direct_limit`
* `algebraic_geometry.prime_spectrum.basic`
* `algebraic_geometry.prime_spectrum.is_open_comap_C`
* `analysis.calculus.fderiv.star`
* `analysis.complex.isometry`
* `analysis.locally_convex.with_seminorms`
* `analysis.normed.mul_action`
* `analysis.normed_space.hahn_banach.extension`
* `data.fintype.quotient`
* `field_theory.separable_degree`
* `linear_algebra.charpoly.to_matrix`
* `linear_algebra.matrix.general_linear_group`
* `linear_algebra.matrix.to_linear_equiv`
* `measure_theory.function.ae_eq_fun`
* `model_theory.quotients`
* `number_theory.modular_forms.congruence_subgroups`
* `ring_theory.adjoin.power_basis`
* `ring_theory.adjoin_root`
* `ring_theory.laurent_series`
* `topology.instances.rat_lemmas`
* `topology.metric_space.gromov_hausdorff_realized`
