Upgrade projects to .NET 10

[gewarren]

Contributes to #12713.

[Copilot]

Pull request overview

Updates a set of C# snippet projects to modern SDK-style project files targeting .NET 10, aligning with the “Modernize all C# code snippets” effort in #12713.

Changes:

• Converted legacy, non-SDK-style .csproj files to SDK-style projects and updated TFMs to net10.0 / net10.0-windows.
• Added Windows Desktop settings (UseWPF, UseWindowsForms) and a few required package references for desktop/snippet compilation.
• Tightened project item inclusion via EnableDefault*Items and explicit <Compile/> / resource item lists.

Reviewed changes

Copilot reviewed 30 out of 30 changed files in this pull request and generated 16 comments.

Show a summary per file

File	Description
snippets/csharp/System/String/Overview/instantiate1.csproj	Migrate to SDK-style and target net10.0 for the String instantiation snippet project.
snippets/csharp/System/IObservableT/Overview/locationtrackercs.csproj	Migrate to SDK-style and target net10.0 for the IObservable snippet project.
snippets/csharp/System/IntPtr/ToPointer/example.csproj	Migrate to SDK-style and target net10.0 for IntPtr.ToPointer snippet project.
snippets/csharp/System/IntPtr/Overview/example.csproj	Migrate to SDK-style and target net10.0 for IntPtr overview snippet project.
snippets/csharp/System/Exception/Overview/customexceptioncs.csproj	Migrate to SDK-style and target net10.0 for custom exception snippet project.
snippets/csharp/System/Convert/IsDBNull/IsDBNull_To_NA_CS.csproj	Migrate to SDK-style, target net10.0-windows, and modernize WinForms/resource items + SqlClient reference.
snippets/csharp/System/Console/Overview/setfont1.csproj	Migrate to SDK-style and target net10.0 for Console set font snippet project.
snippets/csharp/System.Timers/Timer/SynchronizingObject/SynchronizingObjectCS1.csproj	Migrate to SDK-style, target net10.0-windows, and set WinForms-related properties.
snippets/csharp/System.Text.RegularExpressions/Regex/CompileToAssembly/compiletoassembly1.csproj	Migrate to SDK-style and target net10.0 for regex compile-to-assembly snippet project.
snippets/csharp/System.Security/SecureString/.ctor/securestringctor.csproj	Migrate to SDK-style and target net10.0 for SecureString ctor snippet project.
snippets/csharp/System.Runtime.InteropServices/SafeHandle/Overview/safehandle.csproj	Migrate to SDK-style, target net10.0, and add required permissions package reference.
snippets/csharp/System.Runtime.CompilerServices/FixedAddressValueTypeAttribute/Overview/fixedaddress.csproj	Migrate to SDK-style and target net10.0 for FixedAddressValueTypeAttribute snippet project.
snippets/csharp/System.Printing/PrintServer/Overview/PrintServerCreate.csproj	Migrate to SDK-style, target net10.0-windows, and enable WPF for System.Printing sample compilation.
snippets/csharp/System.Printing/PrintQueue/HasPaperProblem/PrinterStatusSurvey.csproj	Migrate to SDK-style, target net10.0-windows, and enable WPF for System.Printing sample compilation.
snippets/csharp/System.Printing/PrintQueue/Commit/Management_PrintTicket.csproj	Migrate to SDK-style, target net10.0-windows, and enable WPF for print ticket sample compilation.
snippets/csharp/System.Printing/PrintJobStatus/Overview/DiagnoseProblematicPrintJob.csproj	Migrate to SDK-style, target net10.0-windows, and enable WPF for print job status sample compilation.
snippets/csharp/System.Printing/LocalPrintServer/GetDefaultPrintQueue/GetPrintObjectPropertiesWithoutReflection.csproj	Migrate to SDK-style, target net10.0-windows, and enable WPF for local print server sample compilation.
snippets/csharp/System.Printing/LocalPrintServer/.ctor/ClonePrinter.csproj	Migrate to SDK-style, target net10.0-windows, and enable WPF for local print server sample compilation.
snippets/csharp/System.Printing/EnumeratedPrintQueueTypes/Overview/EnumerateSubsetOfPrintQueues.csproj	Migrate to SDK-style, target net10.0-windows, and enable WPF for print queue enumeration sample compilation.
snippets/csharp/System.Printing/Collation/Overview/XpsCreate.csproj	Migrate to SDK-style, target net10.0-windows, and enable WinForms/WPF for XPS creation sample compilation.
snippets/csharp/System.IO/StreamWriter/Overview/streamreadwrite.csproj	Migrate to SDK-style and target net10.0 for StreamWriter read/write snippet project.
snippets/csharp/System.IO.Packaging/Package/Overview/PackageWrite.csproj	Migrate to SDK-style, target net10.0-windows, enable WPF, and explicitly include content assets.
snippets/csharp/System.IO.Packaging/Package/GetPart/PackageRead.csproj	Migrate to SDK-style, target net10.0-windows, and enable WPF for package read snippet project.
snippets/csharp/System.IO.Packaging/CertificateEmbeddingOption/Overview/PackageDigitalSignature.csproj	Migrate to SDK-style, target net10.0-windows, enable WPF, and explicitly include content assets.
snippets/csharp/System.ComponentModel.Composition/ExportAttribute/consoleapplication3.csproj	Migrate to SDK-style, target net10.0, and add System.ComponentModel.Composition package reference.
snippets/csharp/System.ComponentModel.Composition.Hosting/DirectoryCatalog/consoleapplication7/consoleapplication7.csproj	Migrate to SDK-style, target net10.0, add package reference, and simplify project reference.
snippets/csharp/System.ComponentModel.Composition.Hosting/DirectoryCatalog/classlibrary1/classlibrary1.csproj	Migrate to SDK-style, target net10.0, and add System.ComponentModel.Composition package reference.
snippets/csharp/System.ComponentModel.Composition.Hosting/CompositionContainer/Overview/consoleapplication1.csproj	Migrate to SDK-style, target net10.0, and add System.ComponentModel.Composition package reference.
snippets/csharp/System.ComponentModel.Composition.Hosting/CompositionContainer/Compose/consoleapplication5.csproj	Migrate to SDK-style, target net10.0, and add System.ComponentModel.Composition package reference.
snippets/csharp/System.Collections.ObjectModel/ObservableCollectionT/BlockReentrancy/ObservableCollection.csproj	Migrate to SDK-style, target net10.0-windows, enable WPF, and explicitly list WPF items.