Document breaking change: AsnEncodedData.RawData setter obsoleted (SYSLIB0065) in .NET 11

[Copilot]

In .NET 11 Preview 6, AsnEncodedData.RawData's setter was marked [Obsolete] (SYSLIB0065) because setting it on derived types (e.g., X509BasicConstraintsExtension) silently desynchronizes the cached decoded state from the raw data—since RawData is non-virtual, derived types can't react to the change.

X509BasicConstraintsExtension decoded = new();
decoded.RawData = extension.RawData; // SYSLIB0065 warning

// Stale cached decode—prints False/False/0 despite the data being set
Console.WriteLine(decoded.CertificateAuthority);

Changes

• New: docs/core/compatibility/cryptography/11/asnencodeddata-rawdata-setter-obsolete.md — breaking change article covering previous/new behavior, reason, and recommended actions (use constructor or CopyFrom)
• New: docs/fundamentals/syslib-diagnostics/syslib0065.md — SYSLIB0065 diagnostic reference with workarounds and suppression guidance
• Updated: docs/fundamentals/syslib-diagnostics/obsoletions-overview.md — adds SYSLIB0065 row to the table
• Updated: docs/core/compatibility/11.md — adds entry under Cryptography
• Updated: docs/core/compatibility/toc.yml — adds new article under .NET 11 Cryptography
• Updated: docs/navigate/tools-diagnostics/toc.yml — adds SYSLIB0065 entry