We specify the LangVersion globally here:

https://github.com/CommunityToolkit/Labs-Windows/blob/60927b0c5975e1ccdbf52a899e044109aca1df1f/Windows.Toolkit.Common.props#L20

(Though maybe this should just be in the Directory.Build.props instead?)

We should update this to be explicitly 10.0.

We should also remove it from being duplicated in the two SG projects so we can manage it centrally:

https://github.com/CommunityToolkit/Labs-Windows/blob/63a00ffa3a4b69da3c68f5d090ad4e0de5eae350/common/CommunityToolkit.Labs.Core.SourceGenerators/CommunityToolkit.Labs.Core.SourceGenerators.csproj#L7

https://github.com/CommunityToolkit/Labs-Windows/blob/18fe7e7d929d6f4545eb7a095b0478ddffd0e3e9/common/CommunityToolkit.Labs.Core.SourceGenerators.XamlNamedPropertyRelay/CommunityToolkit.Labs.Core.SourceGenerators.XamlNamedPropertyRelay.csproj#L7