Revert "Bump runner to dotnet 8" (#3412)

* Revert "Upgrade dotnet sdk to v8.0.303 (#3388)"

This reverts commit dbcaa7cf3d.

* Revert "Bump System.Security.Cryptography.Pkcs from 5.0.0 to 8.0.0 in /src (#3347)"

This reverts commit 3dab1f1fb0.

* Revert "Upgrade dotnet sdk to v8.0.302 (#3346)"

This reverts commit 8f1c723ba0.

* Revert "Bump runner to dotnet 8 (#3345)"

This reverts commit 1e74a8137b.

src/Sdk/Common/Common/Exceptions/PropertyExceptions.cs

@@ -34,7 +34,6 @@ namespace GitHub.Services.Common
 
         public String PropertyName { get; set; }
 
-        [Obsolete]
         [SecurityCritical]
         public override void GetObjectData(SerializationInfo info, StreamingContext context)
         {

src/Sdk/Common/Common/VssException.cs

@@ -127,7 +127,6 @@ namespace GitHub.Services.Common
             EventId = (int)info.GetValue("m_eventId", typeof(int));
         }
 
-        [Obsolete]
         [SecurityCritical]
         public override void GetObjectData(SerializationInfo info, StreamingContext context)
         {