Changes to pass lint check for JDK 23; will have to be rolled back in 10.2 backport

Author: epotyom

lucene/sandbox/src/java/org/apache/lucene/sandbox/facet/utils/DrillSidewaysFacetOrchestrator.java

@@ -49,9 +49,9 @@ public DrillSidewaysFacetOrchestrator addDrillSidewaysBuilder(
     //       manager map instead of a list so that we can be sure that we use the right
     //       collector for the right dimension.
     //       but I think we should do it in a separate PR as it requires changing existing API.
-    int dimIndex = dimToIndex.computeIfAbsent(dim, (x) -> dimToIndex.size());
+    int dimIndex = dimToIndex.computeIfAbsent(dim, (_) -> dimToIndex.size());
     drillSidewaysFacetBuilders
-        .computeIfAbsent(dimIndex, (x) -> new ArrayList<>())
+        .computeIfAbsent(dimIndex, (_) -> new ArrayList<>())
         .add(facetBuilder);
     return this;
   }

lucene/sandbox/src/java/org/apache/lucene/sandbox/facet/utils/FacetOrchestrator.java

@@ -88,7 +88,7 @@ static List<FacetFieldCollectorManager<?>> collectorManagerForBuilders(
     Map<Object, FacetBuilder> buildersUniqueForCollection = new HashMap<>();
     for (FacetBuilder builder : facetBuilders) {
       buildersUniqueForCollection.compute(
-          builder.collectionKey(), (k, v) -> builder.initOrReuseCollector(v));
+          builder.collectionKey(), (_, v) -> builder.initOrReuseCollector(v));
     }
     List<FacetFieldCollectorManager<?>> managers = new ArrayList<>();
     for (FacetBuilder c : buildersUniqueForCollection.values()) {