refactor(e2e): relocate no-node straggler tests

[spalladino]

Relocates the remaining "no-node" straggler tests at the end-to-end/src/ root (tests that don't use the e2e setup() fixture, so they run no Aztec node) to live with the code they actually exercise.

Moved

• e2e_multi_validator/utils.ts → composed/web3signer/multi_validator_keystore_utils.ts. The e2e_multi_validator test was already relocated to multi-node/block-production on the consolidation PR, leaving this utils.ts stranded. Its sole consumer is the web3signer keystore test, so it now lives next to it. The empty e2e_multi_validator/ directory and its two dangling commented-out bootstrap.sh references (pointing at the removed directory) are gone.

• e2e_cheat_codes.test.ts → folded into ethereum/src/test/eth_cheat_codes.test.ts. This test exercises EthCheatCodes directly against a raw anvil with no Aztec node. EthCheatCodes and startAnvil are both defined in @aztec/ethereum (only re-exported by @aztec/aztec/testing), and @aztec/ethereum already has an EthCheatCodes suite plus all needed test deps (viem, foundation). Its mine / timestamp / load-store / etch / impersonate cases were merged into the existing suite, reusing its shared anvil setup. No new dependencies were added; all imports stay intra-package or downward to @aztec/foundation.

• e2e_l1_publisher/ (e2e_l1_publisher.test.ts + write_json.ts) → sequencer-client/src/publisher/. This is a SequencerPublisher integration test: it starts its own anvil, deploys L1 contracts, and drives the publisher directly (no AztecNodeService, no PXE). Its only blocking dependency on @aztec/aztec-node was a single line — import { type AztecNodeConfig, getConfigEnvVars } from '@aztec/aztec-node' — used to build a config object, which would have created a sequencer-client ↔ aztec-node cycle. That dependency was broken by composing sub-configs already reachable from sequencer-client: the config is now built from sequencer-client's own getConfigEnvVars() (SequencerClientConfig, covering l1ChainId, l1RpcUrls, aztecSlotDuration, ethereumSlotDuration, coinbase, feeRecipient, and both sequencerPublisherPreviousL1BlockWait* fields) spread over getL1ContractsConfigEnvVars() (for lagInEpochsForValidatorSet, the one field not on SequencerClientConfig). The unused checkIntervalMs/stallTimeMs overrides are dropped. No package.json or tsconfig changes were needed — every functional dependency (@aztec/ethereum, epoch-cache, world-state, prover-client, blob-client, blob-lib, archiver, stdlib, aztec.js, l1-artifacts) was already present, with @aztec/archiver (for the ArchiverDataSource type) already a devDependency. sendL1ToL2Message has 6+ other end-to-end consumers, so the fixture stays put and is copied as a local test helper (l1_to_l2_messaging.ts) with getLogger() swapped for createLogger from @aztec/foundation/log.

  Test-lane note: the test runs in sequencer-client's standard test lane (default jest config, testRegex over src/**.test.ts), alongside the existing anvil + L1-deploy integration test fee_predictor.test.ts. So this does not introduce a new test profile to the package — sequencer-client already runs heavy anvil-backed tests in that lane.

.test_patterns.yml

The e2e_l1_publisher flake entry (src/e2e_l1_publisher/e2e_l1_publisher.test.ts) was removed, since that path no longer exists. None of the other relocated root tests had .test_patterns.yml entries; they were only matched by the generic src/e2e_!(...).test.ts / src/e2e_*/*.test.ts globs in bootstrap.sh, so their removal leaves no dangling per-file lines.

Part of A-1176