chore(*): add mathlib4 synchronization comments (#18753)
Regenerated from the [port status wiki page](https://github.com/leanprover-community/mathlib/wiki/mathlib4-port-status).
Relates to the following files:
* `algebraic_topology.simplex_category`
* `analysis.hofer`
* `analysis.normed.group.pointwise`
* `analysis.specific_limits.basic`
* `category_theory.idempotents.basic`
* `category_theory.idempotents.functor_categories`
* `category_theory.idempotents.functor_extension`
* `category_theory.idempotents.karoubi`
* `category_theory.idempotents.karoubi_karoubi`
* `data.matrix.pequiv`
* `data.nat.choose.multinomial`
* `group_theory.perm.fin`
* `linear_algebra.affine_space.combination`
* `linear_algebra.finsupp_vector_space`
* `linear_algebra.free_module.basic`
* `linear_algebra.matrix.dot_product`
* `linear_algebra.multilinear.basic`
* `linear_algebra.multilinear.basis`
* `linear_algebra.multilinear.tensor_product`
* `linear_algebra.std_basis`
* `linear_algebra.tensor_product_basis`
* `ring_theory.mv_polynomial.basic`
* `ring_theory.quotient_nilpotent`
* `ring_theory.quotient_noetherian`
* `ring_theory.simple_module`
* `ring_theory.valuation.quotient`
* `set_theory.zfc.basic`
* `topology.algebra.filter_basis`
* `topology.algebra.module.linear_pmap`
* `topology.algebra.module.simple`
* `topology.algebra.star_subalgebra`
* `topology.algebra.uniform_field`
* `topology.algebra.uniform_filter_basis`
* `topology.metric_space.hausdorff_distance`
