Clean up refs to old Windows versions

[gewarren]

Contributes to #12513.

[Copilot]

Pull request overview

This PR updates .NET API reference XML documentation to remove or generalize references to legacy Windows versions (for example, Windows XP/2000/2003/Vista) and to streamline some OS-specific remarks and exception text, as part of the broader effort in #12513.

Changes:

• Generalizes or removes legacy Windows-version-specific remarks across a broad set of API docs.
• Simplifies several PlatformNotSupportedException descriptions and removes some outdated OS-gating statements.
• Cleans up markdown formatting (tables/callouts/extra blank lines) in multiple XML doc files.

Reviewed changes

Copilot reviewed 40 out of 40 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
xml/System/TimeZoneNotFoundException.xml	Updates remarks about Windows time zone registry storage and adjusts overload xref formatting.
xml/System/TimeZoneInfo+AdjustmentRule.xml	Removes XP/Vista-specific registry behavior notes and tightens remarks formatting.
xml/System/DateTime.xml	Removes XP-specific DST conversion caveats and normalizes callout/table formatting in remarks.
xml/System.Security.Principal/WindowsIdentity.xml	Removes Windows Server 2003 domain requirement note and updates TGGAU guidance/link.
xml/System.Security.Principal/WindowsBuiltInRole.xml	Generalizes remarks about Windows local groups; retains UAC note content.
xml/System.Security.Cryptography/RSACryptoServiceProvider.xml	Removes legacy Windows availability note for OAEP padding and trims extra whitespace.
xml/System.Security.Cryptography.X509Certificates/X509ChainElement.xml	Removes XP-only remark and restructures examples section formatting.
xml/System.Security.Cryptography.X509Certificates/X509Certificate2.xml	Removes Windows Server 2003 / RFC3280-specific text and simplifies chaining engine note.
xml/System.Reflection/AssemblyTitleAttribute.xml	Generalizes XP/Vista UI differences into “On Windows …” wording.
xml/System.Printing/PrintSystemJobInfo.xml	Removes XP-specific job ID numbering example and keeps a generalized description.
xml/System.Net/HttpListener.xml	Replaces version-specific PNSE text with a generic message and adjusts usage block formatting.
xml/System.Net.Sockets/UdpClient.xml	Removes XP/2003 default-behavior split for ExclusiveAddressUse and trims whitespace.
xml/System.Net.Sockets/TcpListener.xml	Removes XP/2003 default-behavior split for ExclusiveAddressUse and trims whitespace.
xml/System.Net.Sockets/TcpClient.xml	Removes XP/2003 default-behavior split for ExclusiveAddressUse and trims whitespace.
xml/System.Net.Sockets/SocketOptionLevel.xml	Removes XP IPv6 note about the Advanced Networking Pack.
xml/System.Net.Sockets/Socket.xml	Removes XP/2003 default-behavior split for ExclusiveAddressUse.
xml/System.Net.Sockets/IPProtectionLevel.xml	Removes XP/2003 default-value note and updates wording (“might” vs “may”).
xml/System.Net.Sockets/IOControlCode.xml	Removes XP support statements and formats Winsock constants as code.
xml/System.Net.Security/SslStream.xml	Removes Win9x PNSE exceptions and removes XP/2003-era cipher-algorithm caveats.
xml/System.Net.Security/NegotiateStream.xml	Removes Win9x NotSupportedException statements across server authentication overloads.
xml/System.Net.NetworkInformation/UnicastIPAddressInformation.xml	Rewords PNSE messages (currently still referencing XP) for Windows-only properties.
xml/System.Net.NetworkInformation/NetworkInterface.xml	Rewords PNSE messages (currently still referencing XP) on properties.
xml/System.Net.NetworkInformation/MulticastIPAddressInformation.xml	Rewords PNSE messages (currently still referencing XP) for Windows-only properties.
xml/System.Net.NetworkInformation/IPGlobalProperties.xml	Removes Windows 2000 IPv6 support notes and simplifies remarks.
xml/System.Management/ImpersonationLevel.xml	Removes Windows 2000-only phrasing from Delegate impersonation summary.
xml/System.Drawing/SystemFonts.xml	Removes OS-version-specific font selection description for DialogFont.
xml/System.Drawing.Text/PrivateFontCollection.xml	Removes Windows 2000-era support note from remarks.
xml/System.DirectoryServices/DirectorySearcher.xml	Simplifies PropertiesToLoad documentation and removes Windows 2000 security-descriptor note.
xml/System.DirectoryServices/AuthenticationTypes.xml	Normalizes markdown formatting and generalizes “Windows 2000 locator services” to “Windows”.
xml/System.DirectoryServices.Protocols/LocatorFlags.xml	Removes “Windows 2000 or later” qualifier from summary.
xml/System.DirectoryServices.ActiveDirectory/TrustType.xml	Generalizes “Windows Server 2003 forests” wording to “Windows Server forests”.
xml/System.DirectoryServices.ActiveDirectory/ReplicationCursor.xml	Removes Windows 2000-specific PlatformNotSupportedException documentation.
xml/System.Diagnostics/ProcessStartInfo.xml	Removes XP/2000/2003 distinctions for profile unloading behavior.
xml/System.Diagnostics/Process.xml	Removes legacy Windows-specific exception notes and updates a markdown table layout.
xml/System.Diagnostics/PerformanceCounterCategory.xml	Generalizes/updates Windows access guidance and normalizes callout indentation.
xml/System.Diagnostics/PerformanceCounter.xml	Generalizes “Windows 2000 System Monitor” wording and normalizes callout indentation.
xml/System.Diagnostics/EventLog.xml	Generalizes “Vista/2003” admin requirement wording to “on Windows”.
xml/System.Diagnostics.PerformanceData/CounterType.xml	Removes old Windows Server 2003 Deployment Kit reference but introduces a placeholder remarks.
xml/Microsoft.Win32/RegistryKey.xml	Cleans up exception text formatting and removes legacy Windows 9x/ME OS-specific clauses.
xml/Microsoft.Win32/Registry.xml	Reworks LocalMachine key list formatting and removes a Windows Server 2003-only note.

[BillWagner]

This LGTM. Let's