chore(pruner): set default timeout to None on PrunerBuilder

[joshieDo]

As discussed on: #8127 (comment)

From what I could check, node builder overrides it already anyway.

reth/crates/node/builder/src/launch/common.rs

Lines 278 to 282 in 539c702

	pub fn pruner_builder(&self) -> PrunerBuilder {
	PrunerBuilder::new(self.prune_config().unwrap_or_default())
	.prune_delete_limit(self.chain_spec().prune_delete_limit)
	.timeout(PrunerBuilder::DEFAULT_TIMEOUT)
	}

There are scenarios such reth stage unwind that shouldn't have a timeout.