Fix spurious warp sync failures

Sometimes the nodes spawned from the db snapshot discard the state before
the warp sync nodes have the chance to download it.
We use need to use `--state-pruning archive --blocks-pruning archive` when
generain the db in order to fix this.

substrate/zombienet/0001-basic-warp-sync/generate-warp-sync-database.toml

@@ -11,6 +11,7 @@ chain_spec_path = "chain-spec.json"
   [[relaychain.nodes]]
   name = "alice"
   validator = true
+  args = ["--state-pruning archive --blocks-pruning archive"]
 
   [[relaychain.nodes]]
   name = "bob"