David Britch

Updated the .NET 8 samples to .NET 9, in preparation for removing obsolete APIs. Fixes #515 Fixes #512 Todo: - [x] Cherry pick https://github.com/dotnet/maui-samples/pull/519 into the 9.0 folder. - [x]...

- [x] Update the .csproj files to use `net9-` - [x] Bump the logging package ref - [x] Set minimum versions. - [x] Remove readme's. --- [Associated WorkItem - 318121](https://dev.azure.com/msft-skilling/Content/_workitems/edit/318121)

When bumping the samples to .NET 9, remember to remove the compatibility package from all the .csproj files. --- [Associated WorkItem - 318120](https://dev.azure.com/msft-skilling/Content/_workitems/edit/318120)