Give radix tree setOldestVersion an extra 10 work per call

It seemed to really be important for the skip list. I'm cargo culting
this a little bit here.

ConflictSet.cpp

@@ -2369,6 +2369,9 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
       removalKey = {};
       return;
     }
+    if (keyUpdates == 0) {
+      keyUpdates = 10;
+    }
     removalKeyArena = Arena();
     removalKey = getSearchPath(removalKeyArena, n);
   }
@@ -2394,7 +2397,7 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
 
   Arena removalKeyArena;
   std::span<const uint8_t> removalKey;
-  int64_t keyUpdates = 0;
+  int64_t keyUpdates = 10;
 
   Node *root;
   int64_t rootMaxVersion;