fix SignalR http2 SkipNegotiation error

[WeihanLi]

fix SignalR http2 SkipNegotiation error

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Description

Creating HttpClient for WebSocket SkipNegotiation mode also

Fixes #59303

[Copilot]

Pull Request Overview

This PR fixes an issue where SignalR clients using HTTP/2 with SkipNegotiation mode were not properly creating an HttpClient, which caused errors. The fix ensures that HttpClient is always created regardless of the negotiation and transport settings.

• Removes conditional logic that prevented HttpClient creation in certain scenarios
• Ensures HttpClient is available for all transport configurations

Comments suppressed due to low confidence (1)

src/SignalR/clients/csharp/Http.Connections.Client/src/HttpConnection.cs:151

• The removal of the conditional logic that prevented HttpClient creation in SkipNegotiation + WebSockets-only scenarios should be covered by tests to ensure this fix works correctly and prevent regression.

        _httpClient = CreateHttpClient();

[dotnet-policy-service]

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