chore(LinearAlgebra/Dimension/StrongRankCondition): remove a redundant instance hypothesis (leanprover-community#38265)

The `[Module.Finite R M]` parameter is redundant and can be trivially removed.

I discovered this when investigating breakage in my project in [#general > New simp lemma changes behavior on parameter omission](https://leanprover.zulipchat.com/#narrow/channel/113488-general/topic/New.20simp.20lemma.20changes.20behavior.20on.20parameter.20omission/with/586399020). I don't think it is a direct cause of my problem, but while I am on it, I can make this trivial change.

Author: wwylele

Mathlib/LinearAlgebra/Dimension/StrongRankCondition.lean

@@ -531,7 +531,7 @@ theorem finrank_eq_zero_iff_of_free [Module.Free R M] [Module.Finite R M] :
   simp [Module.finrank, this, Module.rank_zero_iff_of_free]
 
 @[simp]
-theorem finrank_eq_zero_of_subsingleton [Module.Free R M] [Module.Finite R M] [Subsingleton M] :
+theorem finrank_eq_zero_of_subsingleton [Module.Free R M] [Subsingleton M] :
     Module.finrank R M = 0 :=
   (finrank_eq_zero_iff_of_free R M).mpr inferInstance