chore(*): add mathlib4 synchronization comments (#19132)
Regenerated from the [port status wiki page](https://github.com/leanprover-community/mathlib/wiki/mathlib4-port-status).
Relates to the following files:
* `algebra.category.Module.adjunctions`
* `analysis.calculus.darboux`
* `analysis.calculus.deriv.inv`
* `analysis.calculus.diff_cont_on_cl`
* `analysis.calculus.dslope`
* `analysis.inner_product_space.gram_schmidt_ortho`
* `category_theory.abelian.ext`
* `category_theory.abelian.left_derived`
* `category_theory.bicategory.single_obj`
* `data.real.golden_ratio`
* `measure_theory.category.Meas`
* `measure_theory.decomposition.jordan`
* `measure_theory.decomposition.signed_hahn`
* `measure_theory.group.action`
* `measure_theory.group.measure`
* `number_theory.arithmetic_function`
* `number_theory.l_series`
* `number_theory.von_mangoldt`
* `topology.algebra.continuous_monoid_hom`
* `topology.instances.discrete`
* `topology.sheaves.stalks`
* `topology.tietze_extension`
