Update dependency NServiceBus.ClaimCheck to 2.0.0-alpha.6 (#809)

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

Author: dependencyupdates[bot]

src/NServiceBus.Gateway/NServiceBus.Gateway.csproj

@@ -8,7 +8,7 @@
 
   <ItemGroup>
     <PackageReference Include="NServiceBus" Version="10.0.0-alpha.24" />
-    <PackageReference Include="NServiceBus.ClaimCheck" Version="2.0.0-alpha.5" />
+    <PackageReference Include="NServiceBus.ClaimCheck" Version="2.0.0-alpha.6" />
   </ItemGroup>
 
   <ItemGroup>