Remove dead code

src/Runner.Worker/MakefileReader.cs

@@ -0,0 +1,24 @@
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+
+namespace GitHub.Runner.Worker
+{
+    public static class MakefileReader
+    {
+        // Get the dependencies for a target from a Makefile.
+        // Does not recurse into the dependencies of those dependencies.
+        public static List<string> ReadTargetDependencies(IExecutionContext executionContext, string makefile, string target)
+        {
+            var targetToFind = target + ":";
+            var lines = File.ReadLines(makefile);
+            string targetLine = lines.FirstOrDefault(line => line.TrimStart().StartsWith(targetToFind));
+            if (targetLine is null)
+            {
+                return null;
+            }
+
+            return targetLine.Split().Skip(1).ToList();
+        }
+    }
+}