VersionSet::Builder::Apply() does not mutate its argument.

PiperOrigin-RevId: 420533763

db/version_set.cc

@@ -626,7 +626,7 @@ class VersionSet::Builder {
   }
 
   // Apply all of the edits in *edit to the current state.
-  void Apply(VersionEdit* edit) {
+  void Apply(const VersionEdit* edit) {
     // Update compaction pointers
     for (size_t i = 0; i < edit->compact_pointers_.size(); i++) {
       const int level = edit->compact_pointers_[i].first;