Fix IDE0090 (#2211)

src/Runner.Worker/ConditionTraceWriter.cs

@@ -10,7 +10,7 @@ namespace GitHub.Runner.Worker
     {
         private readonly IExecutionContext _executionContext;
         private readonly Tracing _trace;
-        private readonly StringBuilder _traceBuilder = new StringBuilder();
+        private readonly StringBuilder _traceBuilder = new();
 
         public string Trace => _traceBuilder.ToString();