packages.config update can fail if Visual Studio specific component was assumed in a project

[brettfo]

Found via regular log review.

Unhandled exception: System.Exception: Using Msbuild from '/usr/local/dotnet/current/sdk/9.0.100-rc.1.24452.12'.
The imported file "$(MSBuildExtensionsPath32)/Microsoft/VisualStudio/v$(VisualStudioVersion)/SSDT/Microsoft.Data.Tools.Schema.Sql.UnitTesting.targets" does not exist and appears to be part of a Visual Studio component. This file may require MSBuild.exe in order to be imported successfully, and so may fail to build in the dotnet CLI.   /home/dependabot/dependabot-updater/repo/path/to/project.csproj

   at NuGetUpdater.Core.PackagesConfigUpdater.RunNugetUpdate(List`1 updateArgs, List`1 restoreArgs, String projectDirectory, Logger logger) in /opt/nuget/lib/NuGetUpdater/NuGetUpdater.Core/Updater/PackagesConfigUpdater.cs:line 152
   at NuGetUpdater.Core.PackagesConfigUpdater.UpdateDependencyAsync(String repoRootPath, String projectPath, String dependencyName, String previousDependencyVersion, String newDependencyVersion, String packagesConfigPath, Logger logger) in /opt/nuget/lib/NuGetUpdater/NuGetUpdater.Core/Updater/PackagesConfigUpdater.cs:line 82
   at NuGetUpdater.Core.UpdaterWorker.RunUpdaterAsync(String repoRootPath, String projectPath, String dependencyName, String previousDependencyVersion, String newDependencyVersion, Boolean isTransitive) in /opt/nuget/lib/NuGetUpdater/NuGetUpdater.Core/Updater/UpdaterWorker.cs:line 212
   at NuGetUpdater.Core.UpdaterWorker.RunForProjectAsync(String repoRootPath, String projectPath, String dependencyName, String previousDependencyVersion, String newDependencyVersion, Boolean isTransitive) in /opt/nuget/lib/NuGetUpdater/NuGetUpdater.Core/Updater/UpdaterWorker.cs:line 188
   at NuGetUpdater.Core.UpdaterWorker.RunAsync(String repoRootPath, String workspacePath, String dependencyName, String previousDependencyVersion, String newDependencyVersion, Boolean isTransitive) in /opt/nuget/lib/NuGetUpdater/NuGetUpdater.Core/Updater/UpdaterWorker.cs:line 104
   at NuGetUpdater.Core.UpdaterWorker.RunWithErrorHandlingAsync(String repoRootPath, String workspacePath, String dependencyName, String previousDependencyVersion, String newDependencyVersion, Boolean isTransitive) in /opt/nuget/lib/NuGetUpdater/NuGetUpdater.Core/Updater/UpdaterWorker.cs:line 41
   at NuGetUpdater.Core.UpdaterWorker.RunAsync(String repoRootPath, String workspacePath, String dependencyName, String previousDependencyVersion, String newDependencyVersion, Boolean isTransitive, String resultOutputPath) in /opt/nuget/lib/NuGetUpdater/NuGetUpdater.Core/Updater/UpdaterWorker.cs:line 28
   at NuGetUpdater.Cli.Commands.UpdateCommand.<>c__DisplayClass8_0.<<GetCommand>b__0>d.MoveNext() in /opt/nuget/lib/NuGetUpdater/NuGetUpdater.Cli/Commands/UpdateCommand.cs:line 37