Update AWSSDK (#1114)

Co-authored-by: dependencyupdates[bot] <218638057+dependencyupdates[bot]@users.noreply.github.com>

Author: dependencyupdates[bot]

src/NServiceBus.Persistence.DynamoDB/NServiceBus.Persistence.DynamoDB.csproj

@@ -9,7 +9,7 @@
   </PropertyGroup>
 
   <ItemGroup Label="Public dependencies">
-    <PackageReference Include="AWSSDK.DynamoDBv2" Version="4.0.21.6" />
+    <PackageReference Include="AWSSDK.DynamoDBv2" Version="4.0.21.7" />
     <PackageReference Include="NServiceBus" Version="10.2.6" />
   </ItemGroup>