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/CycleInfo.java b/src/main/java/com/google/devtools/build/skyframe/CycleInfo.java
index a410ec5..3c312e4 100644
--- a/src/main/java/com/google/devtools/build/skyframe/CycleInfo.java
+++ b/src/main/java/com/google/devtools/build/skyframe/CycleInfo.java
@@ -20,7 +20,6 @@
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Iterables;
 
-import java.io.Serializable;
 import java.util.HashSet;
 import java.util.Objects;
 import java.util.Set;
@@ -30,7 +29,7 @@
  * head of path to the cycle should be the value itself, or, if the value is actually in the cycle,
  * the cycle should start with the value.
  */
-public class CycleInfo implements Serializable {
+public class CycleInfo {
   private final ImmutableList<SkyKey> cycle;
   private final ImmutableList<SkyKey> pathToCycle;
 
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) {