TodoApp.Uno: NETSDK1198 missing win-AnyCPU.pubxml publish profile warning on windows head

[adrianhall]

Summary

The windows head emits this warning during build:

warning NETSDK1198: A publish profile with the name 'win-AnyCPU.pubxml' was not found in the project. Set the PublishProfile property to a valid file name.

CI run: https://github.com/CommunityToolkit/Datasync/actions/runs/29093946725 (todoapp-uno / windows job)

This is likely pre-existing (unrelated to #524/#525/#526's fixes in PR #533) - it's just newly visible now that the todoapp-uno job's windows sub-job runs as part of CI for the first time. This repo's Directory.Build.props for this sample already suppresses a sibling warning in the same family (NETSDK1201), suggesting this class of noise has been dealt with before for other NETSDK* codes but not yet for NETSDK1198.

Root cause

Uno's WinAppSDK/MSIX packaging pipeline for the Windows head triggers a partial publish-profile lookup (Microsoft.NET.Publish.targets) even during a plain dotnet build, looking for a conventionally-named win-AnyCPU.pubxml publish profile that this sample project doesn't define (and doesn't need, since CI never actually publishes/packages this sample - see the Debug-only, build-only CI rationale already documented in build-samples-todoapp-uno.yml for #521-style reasons). No functional impact: the build still succeeds.

Suggested fix

Add NETSDK1198 to the existing <NoWarn> list in samples/todoapp/TodoApp.Uno/Directory.Build.props (alongside NU1507, NETSDK1201, PRI257), consistent with how the sibling NETSDK1201 warning is already suppressed there for the same underlying reason (build-only CI pipeline, no real publish ever happens).