Bump Microsoft.Data.SqlClient and Serilog.Sinks.MSSqlServer

Bumps [Microsoft.Data.SqlClient](https://github.com/dotnet/sqlclient) and [Serilog.Sinks.MSSqlServer](https://github.com/serilog-mssql/serilog-sinks-mssqlserver). These dependencies needed to be updated together.

Updates `Microsoft.Data.SqlClient` from 5.2.2 to 5.2.2
- [Release notes](https://github.com/dotnet/sqlclient/releases)
- [Changelog](https://github.com/dotnet/SqlClient/blob/main/CHANGELOG.md)
- [Commits](dotnet/SqlClient@v5.2.2...v5.2.2)

Updates `Serilog.Sinks.MSSqlServer` from 6.3.0 to 8.1.0
- [Release notes](https://github.com/serilog-mssql/serilog-sinks-mssqlserver/releases)
- [Changelog](https://github.com/serilog-mssql/serilog-sinks-mssqlserver/blob/dev/CHANGES.md)
- [Commits](serilog-mssql/serilog-sinks-mssqlserver@v6.3.0...v8.1.0)

---
updated-dependencies:
- dependency-name: Microsoft.Data.SqlClient
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: Serilog.Sinks.MSSqlServer
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

DigitalLearningSolutions.Web/DigitalLearningSolutions.Web.csproj

@@ -84,7 +84,7 @@
         <PackageReference Include="NodaTime" Version="3.1.11" />
         <PackageReference Include="Npm" Version="3.5.2" />
         <PackageReference Include="Serilog.AspNetCore" Version="7.0.0" />
-        <PackageReference Include="Serilog.Sinks.MSSqlServer" Version="6.3.0" />
+        <PackageReference Include="Serilog.Sinks.MSSqlServer" Version="8.1.0" />
     </ItemGroup>
 
     <ItemGroup>