[BUG] change token for validation in .net8

[korovindenis]

Description:

This PR addresses an issue related to the validation of the spnegoNegTokenRespKRBAcceptCompleted value. Specifically, the current value causes problems in .NET8 validation as described in dotnet/runtime#105574.

Changes Made:

• Updated the constant spnegoNegTokenRespKRBAcceptCompleted. The new value was obtained from RFC 4559.

Verification:

• The changes have been tested in an environment running .NET8 and .NET6, and the validation issue has been resolved.

Attachments:

example-net.zip The archive contains two utilities compiled for .NET6 and .NET8 These utilities can be used to verify changes across environments with .NET 6 and .NET 8 to ensure that the validation issue has been resolved. The source code for these utilities is available at dotnet/runtime#105574.

net.exe http://example.com/api

Thank you for considering this fix. Please let me know if any other information is required or if there are any additional changes needed.