`--expected-shred-version` is another knob for users to get wrong and is
documentation that can get stale due to cluster restarts. Turns out
it's also generally not required anymore either because:
1. The cluster entrypoint can always be expected to be using the correct
shred version, and that shred version will be adopted by the new node
(earlier this was not the case when the `solana-gossip spy` node on
mainnet-beta.solana.com:8001 ran with shred version 0)
2. On a cluster restart, `--expected-bank-hash` is a much stronger
assertion that the validator is starting from the correct place (and
didn't exist when `--expected-shred-version` was first recommended)