chore(*): add mathlib4 synchronization comments (#19213)
Regenerated from the [port status wiki page](https://github.com/leanprover-community/mathlib/wiki/mathlib4-port-status).
Relates to the following files:
* `algebraic_geometry.Gamma_Spec_adjunction`
* `algebraic_geometry.open_immersion.Scheme`
* `analysis.calculus.implicit`
* `analysis.matrix`
* `analysis.normed_space.matrix_exponential`
* `analysis.normed_space.star.matrix`
* `data.matrix.invertible`
* `linear_algebra.clifford_algebra.basic`
* `linear_algebra.exterior_algebra.basic`
* `number_theory.cyclotomic.basic`
* `number_theory.cyclotomic.primitive_roots`
* `number_theory.number_field.embeddings`
* `number_theory.number_field.units`
* `number_theory.zsqrtd.gaussian_int`
* `ring_theory.dedekind_domain.S_integer`
* `ring_theory.dedekind_domain.adic_valuation`
* `ring_theory.dedekind_domain.finite_adele_ring`
* `ring_theory.discriminant`
* `ring_theory.ideal.norm`
