Add back SingleServerSupport check that was accidentally removed awhile ago

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Hover/HoverEndpoint.cs

@@ -80,7 +80,7 @@ internal sealed class HoverEndpoint(
 
         // Sometimes what looks like a html attribute can actually map to C#, in which case its better to let Roslyn try to handle this.
         // We can only do this if we're in single server mode though, otherwise we won't be delegating to Roslyn at all
-        if (DocumentMappingService.TryMapToGeneratedDocumentPosition(codeDocument.GetCSharpDocument(), positionInfo.HostDocumentIndex, out _, out _))
+        if (SingleServerSupport && DocumentMappingService.TryMapToGeneratedDocumentPosition(codeDocument.GetCSharpDocument(), positionInfo.HostDocumentIndex, out _, out _))
         {
             return null;
         }