TestGetFixesWithDeprioritizedAnalyzerAsync tests a scenario that cannot be reached

[CyrusNajmabadi]

This test validates some sort of analyzer deprioritization system. However the test works by explicitly calling into a test accessor and mutating state that cannot be mutated by normal workspace operations. Specifically, it calls into DiagnosticIncrementalAnalyzer_IncrementalAnalyzer.cs TextDocumentOpenAsync

roslyn/src/LanguageServer/Protocol/Features/Diagnostics/EngineV2/DiagnosticIncrementalAnalyzer_IncrementalAnalyzer.cs

Line 60 in 119402d

private async Task TextDocumentOpenAsync(TextDocument document, CancellationToken cancellationToken)

, which is not hit by any actual product code.

Found in #74984