Remove obsolete serialization - #476

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4, actions/setup-dotnet@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

'SerializableExpressionsTest.Address' defines operator == or operator != but does not override Object.GetHashCode()

'SerializableExpressionsTest.Address' overrides Object.Equals(object o) but does not override Object.GetHashCode()

'SerializableExpressionsTest.Person' defines operator == or operator != but does not override Object.GetHashCode()

'SerializableExpressionsTest.Person' overrides Object.Equals(object o) but does not override Object.GetHashCode()

'SerializableExpressionsTest.Address' defines operator == or operator != but does not override Object.GetHashCode()

'SerializableExpressionsTest.Address' overrides Object.Equals(object o) but does not override Object.GetHashCode()

'SerializableExpressionsTest.Person' defines operator == or operator != but does not override Object.GetHashCode()

'SerializableExpressionsTest.Person' overrides Object.Equals(object o) but does not override Object.GetHashCode()

'SerializableExpressionsTest.Address' defines operator == or operator != but does not override Object.GetHashCode()

'SerializableExpressionsTest.Address' overrides Object.Equals(object o) but does not override Object.GetHashCode()