revlog: remove legacy usage of `_maxdeltachainspan`
All core code is now getting the setting from the DeltaConfig object.
--- a/mercurial/revlogutils/deltas.py Tue Oct 10 11:13:24 2023 +0200
+++ b/mercurial/revlogutils/deltas.py Tue Oct 10 11:16:07 2023 +0200
@@ -608,7 +608,7 @@
textlen = revinfo.textlen
defaultmax = textlen * 4
- maxdist = revlog._maxdeltachainspan
+ maxdist = revlog.delta_config.max_deltachain_span
if not maxdist:
maxdist = deltainfo.distance # ensure the conditional pass
maxdist = max(maxdist, defaultmax)