Fix SSPI ComputeIntegrityCheck with Sign level (#105605)

Fix calling NegotiateAuthentication.ComputeIntegrityCheck on SSPI when
the negotiation context was built with ProtectionLevel.Sign. The
SECQOP_WRAP_NO_ENCRYPT QoP flag should not be set when calling GetMIC as
no encryption is involved and some authentication providers fail when
this is set.

Fix #103461

Co-authored-by: Tomas Weinfurt <tweinfurt@yahoo.com>

src/libraries/System.Net.Security/src/System/Net/NegotiateAuthenticationPal.Windows.cs

@@ -587,8 +587,7 @@ public override unsafe void GetMIC(ReadOnlySpan<byte> message, IBufferWriter<byt
  pBuffers = unmanagedBuffer
  };
 
- uint qop = IsEncrypted ? 0 : Interop.SspiCli.SECQOP_WRAP_NO_ENCRYPT;
- int errorCode = Interop.SspiCli.MakeSignature(ref _securityContext._handle, qop, ref sdcInOut, 0);
+ int errorCode = Interop.SspiCli.MakeSignature(ref _securityContext._handle, 0, ref sdcInOut, 0);
 
  if (errorCode != 0)
  {