Move WorkspaceFileValue to the lib.packages directory, since that's where WorkspaceFactory and the rest of its kind are. Also remove an unused method in WorkspaceFactory.

PiperOrigin-RevId: 231632979
diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/FilesystemValueCheckerTest.java b/src/test/java/com/google/devtools/build/lib/skyframe/FilesystemValueCheckerTest.java
index f35556c..62691af 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/FilesystemValueCheckerTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/FilesystemValueCheckerTest.java
@@ -39,6 +39,7 @@
 import com.google.devtools.build.lib.analysis.ServerDirectories;
 import com.google.devtools.build.lib.cmdline.PackageIdentifier;
 import com.google.devtools.build.lib.events.NullEventHandler;
+import com.google.devtools.build.lib.packages.WorkspaceFileValue;
 import com.google.devtools.build.lib.pkgcache.PathPackageLocator;
 import com.google.devtools.build.lib.skyframe.DirtinessCheckerUtils.BasicFilesystemDirtinessChecker;
 import com.google.devtools.build.lib.skyframe.ExternalFilesHelper.ExternalFileAction;
@@ -149,7 +150,7 @@
     skyFunctions.put(SkyFunctions.WORKSPACE_AST,
         new WorkspaceASTFunction(TestRuleClassProvider.getRuleClassProvider()));
     skyFunctions.put(
-        SkyFunctions.WORKSPACE_FILE,
+        WorkspaceFileValue.WORKSPACE_FILE,
         new WorkspaceFileFunction(
             TestRuleClassProvider.getRuleClassProvider(),
             TestConstants.PACKAGE_FACTORY_BUILDER_FACTORY_FOR_TESTING