fix(Algebra/MonoidAlgebra/Defs): rename AddMonoidAlgebra.coeff_zero_zero (#41783)

Co-authored-by: Yaël Dillies <yael.dillies@gmail.com>
Co-authored-by: YaelDillies <14090593+YaelDillies@users.noreply.github.com>

Author: mathlib-splicebot[bot]

Mathlib/Algebra/MonoidAlgebra/Defs.lean

@@ -468,9 +468,12 @@ instance one : One R[M] where one := single 1 1
 @[to_additive (dont_translate := R) one_def]
 lemma one_def : (1 : R[M]) = single 1 1 := rfl
 
-@[to_additive (attr := simp) (dont_translate := R)]
+@[to_additive (attr := simp) (dont_translate := R) coeff_one_zero]
 lemma coeff_one_one : (1 : R[M]).coeff 1 = 1 := by simp [one_def]
 
+@[deprecated (since := "2026-07-15")]
+alias _root_.AddMonoidAlgebra.coeff_zero_zero := AddMonoidAlgebra.coeff_one_zero
+
 end One
 
 section Mul