go/oasis-node: Bump default pruning config to 250_000 versions

Update defaults to 250_000 versions, so that node has enough
consensus and runtime state to create at least two chekpoints
if the checkpoint interval is 100_000. At the same time this
is still far from the number of versions, that makes Sapphire
pruning prohibitively slow.

Author: martintomazic

.changelog/6449.trivial.md

@@ -235,7 +235,7 @@ func DefaultConfig() Config {
 		UpgradeStopDelay: time.Minute,
 		Prune: PruneConfig{
 			Strategy: PruneStrategyNone,
-			NumKept:  3600,
+			NumKept:  250_000,
 			Interval: 2 * time.Minute,
 		},
 		Checkpointer: CheckpointerConfig{

go/consensus/cometbft/config/config.go

@@ -521,7 +521,7 @@ func DefaultConfig() Config {
 		Prune: PruneConfig{
 			Strategy: "none",
 			Interval: 2 * time.Minute,
-			NumKept:  600,
+			NumKept:  250_000,
 		},
 		Indexer: IndexerConfig{
 			BatchSize: 1000,