Remove the $resolved_toolchains_internal attribute.

Closes #8002.

PiperOrigin-RevId: 243290817
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/ConfiguredTargetFunction.java b/src/main/java/com/google/devtools/build/lib/skyframe/ConfiguredTargetFunction.java
index a933c8e..82785eb 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/ConfiguredTargetFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/ConfiguredTargetFunction.java
@@ -34,7 +34,6 @@
 import com.google.devtools.build.lib.analysis.DependencyResolver.DependencyKind;
 import com.google.devtools.build.lib.analysis.DependencyResolver.InconsistentAspectOrderException;
 import com.google.devtools.build.lib.analysis.EmptyConfiguredTarget;
-import com.google.devtools.build.lib.analysis.PlatformSemantics;
 import com.google.devtools.build.lib.analysis.ResolvedToolchainContext;
 import com.google.devtools.build.lib.analysis.TargetAndConfiguration;
 import com.google.devtools.build.lib.analysis.ToolchainResolver;
@@ -451,7 +450,7 @@
     if (rule.getRuleClassObject().executionPlatformConstraintsAllowed()
         == ExecutionPlatformConstraintsAllowed.PER_TARGET) {
       execConstraintLabels.addAll(
-          mapper.get(PlatformSemantics.EXEC_COMPATIBLE_WITH_ATTR, BuildType.LABEL_LIST));
+          mapper.get(RuleClass.EXEC_COMPATIBLE_WITH_ATTR, BuildType.LABEL_LIST));
     }
 
     return execConstraintLabels.build();