mathlib

308f6d03 - chore(*): add mathlib4 synchronization comments (#17790)

chore(*): add mathlib4 synchronization comments (#17790) Regenerated from the [port status wiki page](https://github.com/leanprover-community/mathlib/wiki/mathlib4-port-status). Relates to the following PRs: * `algebra.order.sub.canonical`: https://github.com/leanprover-community/mathlib4/pull/814 * `category_theory.category.Rel`: https://github.com/leanprover-community/mathlib4/pull/822 * `category_theory.category.basic`: https://github.com/leanprover-community/mathlib4/pull/749 * `category_theory.functor.basic`: https://github.com/leanprover-community/mathlib4/pull/749 * `category_theory.functor.category`: https://github.com/leanprover-community/mathlib4/pull/749 * `category_theory.functor.functorial`: https://github.com/leanprover-community/mathlib4/pull/822 * `category_theory.isomorphism`: https://github.com/leanprover-community/mathlib4/pull/749 * `category_theory.natural_transformation`: https://github.com/leanprover-community/mathlib4/pull/749 * `category_theory.thin`: https://github.com/leanprover-community/mathlib4/pull/822 * `combinatorics.quiver.basic`: https://github.com/leanprover-community/mathlib4/pull/749 * `combinatorics.quiver.path`: https://github.com/leanprover-community/mathlib4/pull/811 * `data.psigma.order`: https://github.com/leanprover-community/mathlib4/pull/815 * `data.stream.defs`: https://github.com/leanprover-community/mathlib4/pull/665 * `order.boolean_algebra`: https://github.com/leanprover-community/mathlib4/pull/794 * `order.heyting.basic`: https://github.com/leanprover-community/mathlib4/pull/793 * `order.rel_iso.group`: https://github.com/leanprover-community/mathlib4/pull/813