Bump NServiceBus.Transport.SqlServer from 8.1.3 to 8.1.6 in /src

Bumps [NServiceBus.Transport.SqlServer](https://github.com/Particular/NServiceBus.SqlServer) from 8.1.3 to 8.1.6.
- [Release notes](https://github.com/Particular/NServiceBus.SqlServer/releases)
- [Commits](Particular/NServiceBus.SqlServer@8.1.3...8.1.6)

---
updated-dependencies:
- dependency-name: NServiceBus.Transport.SqlServer
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

src/NServiceBus.NHibernate.AcceptanceTests.SqlTransport/NServiceBus.NHibernate.AcceptanceTests.SqlTransport.csproj

@@ -13,7 +13,7 @@
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.11.1" />
     <PackageReference Include="NHibernate" Version="5.5.2" />
     <PackageReference Include="NServiceBus.AcceptanceTests.Sources" Version="9.2.2" GeneratePathProperty="true" />
-    <PackageReference Include="NServiceBus.Transport.SqlServer" Version="8.1.3" />
+    <PackageReference Include="NServiceBus.Transport.SqlServer" Version="8.1.6" />
     <PackageReference Include="NUnit" Version="4.2.2" />
     <PackageReference Include="NUnit.Analyzers" Version="4.4.0" />
     <PackageReference Include="NUnit3TestAdapter" Version="4.6.0" />