revlog: remove legacy usage of `_deltabothparents`
All core code is now getting the setting from the DeltaConfig object.
--- a/mercurial/revlogutils/deltas.py Tue Oct 10 11:05:54 2023 +0200
+++ b/mercurial/revlogutils/deltas.py Tue Oct 10 11:07:15 2023 +0200
@@ -924,7 +924,7 @@
# exclude already lazy tested base if any
parents = [p for p in (p1, p2) if p != nullrev]
- if not revlog._deltabothparents and len(parents) == 2:
+ if not revlog.delta_config.delta_both_parents and len(parents) == 2:
parents.sort()
# To minimize the chance of having to build a fulltext,
# pick first whichever parent is closest to us (max rev)