Delete redundant @AutoCodec annotation on NonRuleConfiguredTargetValue.

The ConfiguredTargetValueCodec already provides serialization for
NonRuleConfiguredTargetValue.

Adds clarifying comments.

PiperOrigin-RevId: 840366686
Change-Id: I53e8d8ec7412bf752f8f816944953ab92de044dc

Author: aoeui

src/main/java/com/google/devtools/build/lib/skyframe/NonRuleConfiguredTargetValue.java

@@ -13,41 +13,29 @@
 // limitations under the License.
 package com.google.devtools.build.lib.skyframe;
 
-
 import com.google.common.base.MoreObjects;
 import com.google.devtools.build.lib.analysis.ConfiguredTarget;
 import com.google.devtools.build.lib.analysis.ConfiguredTargetValue;
-import com.google.devtools.build.lib.analysis.configuredtargets.RuleConfiguredTarget;
 import com.google.devtools.build.lib.collect.nestedset.NestedSet;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.ThreadSafe;
 import com.google.devtools.build.lib.packages.Package;
 import com.google.devtools.build.lib.packages.TargetData;
-import com.google.devtools.build.lib.skyframe.serialization.VisibleForSerialization;
-import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import javax.annotation.Nullable;
 
 /** A non-rule configured target in the context of a Skyframe graph. */
 @Immutable
 @ThreadSafe
-// Reached via all ConfiguredTarget implementations except RuleConfiguredTarget.
-@AutoCodec(explicitlyAllowClass = RuleConfiguredTarget.class)
 public final class NonRuleConfiguredTargetValue
     extends AbstractConfiguredTargetValue<ConfiguredTarget> implements ConfiguredTargetValue {
 
-  private TargetData targetData;
-
-  @AutoCodec.Instantiator
-  @VisibleForSerialization
-  NonRuleConfiguredTargetValue(
-      ConfiguredTarget configuredTarget) {
-    // Transitive packages are not serialized.
-    this(configuredTarget, null);
-  }
+  @Nullable // Non-null when this is an alias of a remotely fetched ConfiguredTarget.
+  private final TargetData targetData;
 
   NonRuleConfiguredTargetValue(
       ConfiguredTarget configuredTarget, @Nullable NestedSet<Package.Metadata> transitivePackages) {
     super(configuredTarget, transitivePackages);
+    this.targetData = null;
   }
 
   NonRuleConfiguredTargetValue(