chore(*): add mathlib4 synchronization comments (#19157)
Regenerated from the [port status wiki page](https://github.com/leanprover-community/mathlib/wiki/mathlib4-port-status).
Relates to the following files:
* `algebra.lie.tensor_product`
* `analysis.calculus.cont_diff`
* `analysis.calculus.inverse`
* `analysis.calculus.lagrange_multipliers`
* `analysis.complex.real_deriv`
* `analysis.special_functions.exp_deriv`
* `analysis.special_functions.sqrt`
* `category_theory.monoidal.functor_category`
* `linear_algebra.tensor_power`
* `number_theory.sum_four_squares`
Author
github-actions[bot]
