Keep older clients and plain-HTTP deployments working - #2121

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

Dereference of a possibly null reference.

'IMiscellaneousClient.RenderArbitraryMarkdown(NewArbitraryMarkdown)' is obsolete: 'This client is being deprecated and will be removed in the future. Use MarkdownClient.RenderArbitraryMarkdown instead.'

Nullability of reference types in value of type 'Dictionary<Guid, (string PayloadJson, string? OutcomeJson)>' doesn't match target type 'IReadOnlyDictionary<Guid, (string? PayloadJson, string? OutcomeJson)>'.

Dereference of a possibly null reference.

Non-nullable property 'RecomputedHash' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.

Non-nullable property 'StoredHash' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.

Possible null reference assignment.

Possible null reference assignment.

Possible null reference assignment.

The type 'TRequest' cannot be used as type parameter 'TRequest' in the generic type or method 'IPipelineBehavior<TRequest, TResponse>'. Nullability of type argument 'TRequest' doesn't match 'notnull' constraint.