feat: an abstract continuous functional calculus for non-unital algebras (#11221)

Author: j-loreaux

Mathlib.lean

@@ -3840,6 +3840,7 @@ import Mathlib.Topology.ContinuousFunction.ContinuousMapZero
 import Mathlib.Topology.ContinuousFunction.FunctionalCalculus
 import Mathlib.Topology.ContinuousFunction.Ideals
 import Mathlib.Topology.ContinuousFunction.LocallyConstant
+import Mathlib.Topology.ContinuousFunction.NonUnitalFunctionalCalculus
 import Mathlib.Topology.ContinuousFunction.Ordered
 import Mathlib.Topology.ContinuousFunction.Polynomial
 import Mathlib.Topology.ContinuousFunction.Sigma