Fix flaky tests

[NingLin-P]

This PR tries to fix some flaky tests:

#1399
I have dug into prune_known() and seems what it does is indeed what we expected, and I have another guess about the failure:
https://github.com/subspace/subspace/blob/317f83a58670e51298703d9e480a004f6986df5b/domains/client/domain-executor/src/tests.rs#L917-L920

namely, after the block that contains the submit_bundle tx is imported and before the call of prune_tx_from_pool, the background worker txpool-notifications handled the imported block, which will ban all the tx of the block, thus the tx is already banned before we calling prune_tx_from_pool.

the solution is to wait 1ms before calling clear_stale in prune_tx_from_pool, because we have already set ban_time to 0, wait a few more times will ensure the bans will be removed in clear_stale as the ban time must be passed.

#1219
This PR is not a complete fix for this issue as we still not figure out why the last K blocks will be pruned such fast (may be related to configuration, local storage of the node, etc).

But this PR should workaround most of the damage as the pruned block will be skipped as the chain grows, and things will back to normal.

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[nazar-pc]

This PR is not a complete fix for this issue as we still not figure out why the last K blocks will be pruned such fast (may be related to configuration, local storage of the node, etc).

In CI confirmation depth is 5, but in practice none of the blocks should be pruned because they will not be deep enough after changes #1541, none of the blocks should be finalized and pruned unless you have a few gigabytes worth of blockchain history.

[NingLin-P]

none of the blocks should be finalized and pruned unless you have a few gigabytes worth of blockchain history.

There are some differences between finality and canonicalization:
https://github.com/paritytech/substrate/blob/fe1f8ba1c4f23931ae89c1ada35efb3d908b50f5/client/state-db/src/lib.rs#L32-L42

and the blocks of non-canonical branches may get pruned upon canonicalization:
https://github.com/paritytech/substrate/blob/fe1f8ba1c4f23931ae89c1ada35efb3d908b50f5/client/state-db/src/noncanonical.rs#L384-L387

[liuchengxu]

The reasoning of banned tx makes sense to me. I'm not pretty sure about the second commit, but the code change is fine. BTW, I think we can at least improve the log to include the block number so that next time we can have more context to investigate.

https://github.com/subspace/subspace/blob/317f83a58670e51298703d9e480a004f6986df5b/crates/subspace-transaction-pool/src/bundle_validator.rs#L278-L281