chore: remove upstreamed lemma isOpen_maximalIdeal_pow

[dwrensha]

Removes IsLocalRing.isOpen_maximalIdeal_pow', which was added upstream as IsLocalRing.isOpen_maximalIdeal_pow in leanprover-community/mathlib4#23757.

The type of the upstream version differs only in the order of its typeclass paramters:

#check isOpen_maximalIdeal_pow
/-
IsLocalRing.isOpen_maximalIdeal_pow'.{u_1} (R : Type u_1) [CommRing R] [IsLocalRing R]
 [TopologicalSpace R] [IsTopologicalRing R] [IsNoetherianRing R] [CompactSpace R] [T2Space R]
 (n : ℕ) : IsOpen ↑(maximalIdeal R ^ n)
-/

#check isOpen_maximalIdeal_pow'
/-
IsLocalRing.isOpen_maximalIdeal_pow.{u_1} (R : Type u_1) [CommRing R] [TopologicalSpace R]
  [IsTopologicalRing R] [CompactSpace R] [T2Space R] [IsLocalRing R] [IsNoetherianRing R]
  (n : ℕ) : IsOpen ↑(maximalIdeal R ^ n)
-/

[kbuzzard]

Thanks!