chore(deps): bump gravity-reth to 408ef602 (audit-710 InvalidTransaction filter) + e2e

[nekomoto911]

Summary

• Bumps greth from 0adbb4c9 to 408ef602 (fix(filter): close gravity-audit#710 + add pipe panic smoke test gravity-reth#357), which closes the remaining 6 of 9 revm::InvalidTransaction variants at the admission filter (gas/priority fee, empty authList, balance, chainId, EIP-3607 sender-with-code). Closes the audit-710 follow-up: the executor cannot recover from EVMError, so the filter is the only practical defense.
• Adds two Prague E2E cases in cluster_test_cases/prague/test_eip7702.py:
  • P-B7 — hand-built type-4 tx with empty authorizationList (eth_account refuses to sign the malformed form, so we encode RLP directly — a hostile client would too). Oracle: RPC rejects at admission + chain keeps producing blocks (gravity_node didn't panic on InvalidTransaction::EmptyAuthorizationList).
  • P-B8 — EIP-3607 designator carve-out: an EOA with an installed 7702 delegation designator can still send a plain type-2 tx with its own key. Without the carve-out the filter would silently break every 7702-based smart-account flow.

Test plan

• RUSTFLAGS="--cfg tokio_unstable" cargo check -p gravity_node — passes
• RUSTFLAGS="--cfg tokio_unstable" cargo build -p gravity_node -p gravity_cli --profile quick-release — passes
• python3 gravity_e2e/runner.py prague — 13/13 passed in 92s (existing P-B1..P-B6 + EIP-2935 cases unaffected; new P-B7 confirmed pool-reject Web3RPCError -32000 "no items in authorization list for EIP7702 transaction"; P-B8 delegated EOA tx succeeded)