Update minimum supported date for .NET 11

[gewarren]

Contributes to dotnet/docs#50894.

[dotnet-policy-service]

Tagging subscribers to this area: @dotnet/area-system-globalization

[Copilot]

Pull request overview

This PR updates the JapaneseCalendar documentation and code examples to reflect the new minimum supported date for .NET 11. The minimum supported date changes from September 8, 1868 to October 23, 1868 C.E. in the Gregorian calendar.

Key changes:

• Updated MinSupportedDateTime property documentation to specify October 23, 1868 as the new minimum date for .NET 11
• Added version notes clarifying the date difference between .NET 10 and earlier versus .NET 11
• Removed ?displayProperty=nameWithType from various xref property references for cleaner formatting
• Modernized C# code examples to use top-level statements and target constructors
• Reformatted and updated code snippet output to reflect the new dates

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
xml/System.Globalization/JapaneseCalendar.xml	Updated MinSupportedDateTime documentation, added version notes, cleaned up xref formatting, and corrected whitespace
snippets/csharp/System.Globalization/JapaneseCalendar/MaxSupportedDateTime/japanesecalendar_minmax.cs	Modernized code to top-level statements, updated expected output for .NET 11 with new minimum date
snippets/csharp/System.Globalization/JapaneseCalendar/MaxSupportedDateTime/Project.csproj	Changed output type to Exe and target framework to net10.0
snippets/visualbasic/System.Globalization/JapaneseCalendar/MaxSupportedDateTime/japanesecalendar_minmax.vb	Reformatted code, updated expected output for .NET 11 with new minimum date
snippets/visualbasic/System.Globalization/JapaneseCalendar/MaxSupportedDateTime/Project.vbproj	Added new project file targeting net10.0 with Exe output type

[tarekgh]

Thanks @gewarren

[BillWagner]

This LGTM, once you address the open conversations.