Bump NServiceBus.Transport.SqlServer from 8.1.7 to 8.1.8 in /src (#4878)

Bumps [NServiceBus.Transport.SqlServer](https://github.com/Particular/NServiceBus.SqlServer) from 8.1.7 to 8.1.8.
- [Release notes](https://github.com/Particular/NServiceBus.SqlServer/releases)
- [Commits](Particular/NServiceBus.SqlServer@8.1.7...8.1.8)

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

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

src/Directory.Packages.props

@@ -44,7 +44,7 @@
     <PackageVersion Include="NServiceBus.Transport.AzureServiceBus" Version="5.0.0" />
     <PackageVersion Include="NServiceBus.Transport.AzureStorageQueues" Version="13.0.2" />
     <PackageVersion Include="NServiceBus.Transport.Msmq.Sources" Version="3.0.2" />
-    <PackageVersion Include="NServiceBus.Transport.SqlServer" Version="8.1.7" />
+    <PackageVersion Include="NServiceBus.Transport.SqlServer" Version="8.1.8" />
     <PackageVersion Include="NServiceBus.Transport.PostgreSql" Version="8.1.7" />
     <PackageVersion Include="NuGet.Versioning" Version="6.13.2" />
     <PackageVersion Include="NUnit" Version="4.3.2" />