chore: remove redundant words (#34523)

Author: sunxunle

aspnetcore/client-side/dotnet-interop/index.md

@@ -131,7 +131,7 @@ Some types don't have a default type mapping. For example, a `long` can be marsh
 
 The following type mapping scenarios are supported:
 
-* Passing <xref:System.Action> or <xref:System.Func%601> as parameters, which are are marshalled as callable JS methods. This allows .NET code to invoke listeners in response to JS callbacks or events.
+* Passing <xref:System.Action> or <xref:System.Func%601> as parameters, which are marshalled as callable JS methods. This allows .NET code to invoke listeners in response to JS callbacks or events.
 * Passing JS references and .NET managed object references in either direction, which as marshaled as proxy objects and kept alive across the interop boundary until the proxy is garbage collected.
 * Marshalling asynchronous JS methods or a [JS `Promise`](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Promise) with a <xref:System.Threading.Tasks.Task> result, and vice versa. 
 

aspnetcore/fundamentals/openapi/include-metadata.md

@@ -566,7 +566,7 @@ If the additional properties of a schema should only have values of a specific t
 
 #### Polymorphic types
 
-Use the [`[JsonPolymorphic]`](xref:System.Text.Json.Serialization.JsonPolymorphicAttribute) and [`[JsonDerivedType]`](xref:System.Text.Json.Serialization.JsonDerivedTypeAttribute) attributes on a parent class to to specify the discriminator field and subtypes for a polymorphic type.
+Use the [`[JsonPolymorphic]`](xref:System.Text.Json.Serialization.JsonPolymorphicAttribute) and [`[JsonDerivedType]`](xref:System.Text.Json.Serialization.JsonDerivedTypeAttribute) attributes on a parent class to specify the discriminator field and subtypes for a polymorphic type.
 
 The [`[JsonDerivedType]`](xref:System.Text.Json.Serialization.JsonDerivedTypeAttribute) adds the discriminator field to the schema for each subclass, with an enum specifying the specific discriminator value for the subclass. This attribute also modifies the constructor of each derived class to set the discriminator value.