ErrorInfo and CycleInfo don't need to be serializable

RELNOTES:

--
MOS_MIGRATED_REVID=104341630
diff --git a/src/main/java/com/google/devtools/build/skyframe/ErrorInfo.java b/src/main/java/com/google/devtools/build/skyframe/ErrorInfo.java
index 1c07051..72e7ab4 100644
--- a/src/main/java/com/google/devtools/build/skyframe/ErrorInfo.java
+++ b/src/main/java/com/google/devtools/build/skyframe/ErrorInfo.java
@@ -22,7 +22,6 @@
 import com.google.devtools.build.skyframe.SkyFunctionException.ReifiedSkyFunctionException;
 
 import java.io.IOException;
-import java.io.Serializable;
 import java.util.Collection;
 
 import javax.annotation.Nullable;
@@ -32,7 +31,7 @@
  *
  * <p>This is intended only for use in alternative {@code MemoizingEvaluator} implementations.
  */
-public class ErrorInfo implements Serializable {
+public class ErrorInfo {
 
   /** Create an ErrorInfo from a {@link ReifiedSkyFunctionException}. */
   public static ErrorInfo fromException(ReifiedSkyFunctionException skyFunctionException) {