Remove traces of the "include directory" from include scanning, and clarify that it is only used by build-info actions: the native cc_inc_library rule is gone, and that was where the include directory was used in a special way.

PiperOrigin-RevId: 433150940
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/RuleContext.java b/src/main/java/com/google/devtools/build/lib/analysis/RuleContext.java
index b0d823a..5e40f16 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/RuleContext.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/RuleContext.java
@@ -279,8 +279,9 @@
     return getConfiguration().getBinDirectory(getLabel().getRepository());
   }
 
-  public ArtifactRoot getIncludeDirectory() {
-    return getConfiguration().getIncludeDirectory(getLabel().getRepository());
+  @SuppressWarnings("Unused") // Goal is to migrate here.
+  public ArtifactRoot getBuildInfoDirectory() {
+    return getConfiguration().getBuildInfoDirectory(getLabel().getRepository());
   }
 
   public ArtifactRoot getGenfilesDirectory() {