Add TODO for removing LipDataTransitionRuleSet when LIPO is gone

Followup to a5d00d6db98a09b0a644db77301d9b6ed4f2a2ff

PiperOrigin-RevId: 185001965
diff --git a/src/main/java/com/google/devtools/build/lib/bazel/rules/BazelRuleClassProvider.java b/src/main/java/com/google/devtools/build/lib/bazel/rules/BazelRuleClassProvider.java
index c409ce4..36bf355 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/rules/BazelRuleClassProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/rules/BazelRuleClassProvider.java
@@ -324,6 +324,7 @@
       ImmutableSet.of(
           // Rules defined before LipoDataTransitionRuleSet will fail when trying to declare a data
           // transition.
+          // TODO(b/73071922): remove this when LIPO support is phased out
           LipoDataTransitionRuleSet.INSTANCE,
           BAZEL_SETUP,
           CoreRules.INSTANCE,