set prune height to 1_000_000MB

Previously, prune=10000 was causing flushes of the UTXO set when block
pruning was taking please, resulting in logs like:

❯ zcat 32000-instrumented-pr-debug.log.gz | rg UTXO
2026-02-12T07:22:57Z * Using 31990.0 MiB for in-memory UTXO set (plus up to 286.1 MiB of unused mempool space)
2026-02-12T07:28:51Z [warning] Flushing large (2 GiB) UTXO set to disk, it may take several minutes
2026-02-12T07:33:10Z [warning] Flushing large (3 GiB) UTXO set to disk, it may take several minutes
2026-02-12T07:37:23Z [warning] Flushing large (4 GiB) UTXO set to disk, it may take several minutes
2026-02-12T07:42:03Z [warning] Flushing large (4 GiB) UTXO set to disk, it may take several minutes
2026-02-12T07:46:34Z [warning] Flushing large (5 GiB) UTXO set to disk, it may take several minutes
2026-02-12T07:51:10Z [warning] Flushing large (6 GiB) UTXO set to disk, it may take several minutes
2026-02-12T07:55:57Z [warning] Flushing large (7 GiB) UTXO set to disk, it may take several minutes
2026-02-12T08:00:35Z [warning] Flushing large (8 GiB) UTXO set to disk, it may take several minutes
2026-02-12T08:05:16Z [warning] Flushing large (8 GiB) UTXO set to disk, it may take several minutes
2026-02-12T08:10:00Z [warning] Flushing large (8 GiB) UTXO set to disk, it may take several minutes
2026-02-12T08:14:36Z [warning] Flushing large (8 GiB) UTXO set to disk, it may take several minutes
2026-02-12T08:16:47Z [warning] Flushing large (8 GiB) UTXO set to disk, it may take several minutes

and generally interrupting benchmarking. Remove this effect by setting
prune to such a high value it will never trigger.

Prune is **required** to permit us to continue syncing from a pruned
datadir.

Author: willcl-ark

bench/benchmark_config.py

@@ -55,7 +55,7 @@ def from_toml(cls, path: Path) -> BenchmarkConfig:
             stopatheight = 855000
             chain = "main"
             connect = "..."
-            prune = 10000
+            prune = 1000000
             daemon = false
             printtoconsole = false
 

bench/configs/nightly.toml

@@ -14,7 +14,7 @@ runs = 2
 stopatheight = 900000
 chain = "main"
 connect = "148.251.128.115:33333" # accepts whitelisted ip addrs only
-prune = 10000
+prune = 1000000
 daemon = false
 printtoconsole = false
 

bench/configs/pr.toml

@@ -14,7 +14,7 @@ runs = 2
 stopatheight = 900000
 chain = "main"
 connect = "148.251.128.115:33333"
-prune = 10000
+prune = 1000000
 daemon = false
 printtoconsole = false
 

bench/configs/test-signet.toml

@@ -13,7 +13,7 @@ runs = 1
 [bitcoind]
 stopatheight = 10000
 chain = "signet"
-prune = 1000
+prune = 1000000
 daemon = false
 printtoconsole = false