test: flag e2e_multi_validator_node_key_store P2P tx-dropped failure as flake

[AztecBot]

Summary

Add a .test_patterns.yml entry to flag the multi-validator web3signer suite as a flake when the first concurrently-submitted tx is dropped by the P2P layer before reaching a proposer. This is what dequeued PR #23344 from the merge queue at 2026-05-23T09:17 (run 26328618812).

Investigation

• Failing merge-queue run: https://github.com/AztecProtocol/aztec-packages/actions/runs/26328618812
• Failing ci job: https://github.com/AztecProtocol/aztec-packages/actions/runs/26328618812/job/77510713955
• x8-full row that failed (1325s): http://ci.aztec-labs.com/162be3cbb19cd1b9
• Nested test-engine row: http://ci.aztec-labs.com/1ffc06822777293f
• Inner jest sublog: http://ci.aztec-labs.com/9a5fa90aa18f62e7

Jest output:

FAIL src/composed/web3signer/e2e_multi_validator_node_key_store.test.ts
  e2e_multi_validator_node
    ✕ should build blocks & attest with multiple validator keys (129296 ms)

  ● e2e_multi_validator_node › should build blocks & attest with multiple validator keys

    Transaction 0x26a078118c6ca2566de5b2405b745cc211dfd53a9bdcd478d068c2e13994a6a3 was dropped. Reason: Tx dropped by P2P node

      at async Promise.all (index 0)
      at Object.<anonymous> (composed/web3signer/e2e_multi_validator_node_key_store.test.ts:410:33)

Line 410 is inside the await Promise.all(sentTransactionPromises.map(async … => waitForTx(aztecNode, txHash))) block. The first of the concurrently-submitted txs never propagates and waitForTx resolves to a dropped receipt; this is a transient P2P-propagation flake under the proposer-pipelining migration in #23482.

Why a new entry?

There is no existing entry covering this suite. The unique error signature is Tx dropped by P2P node, which appears in the receipt's error field rendered by waitForTx.

Follow-up

Proper fix: investigate why the first tx is occasionally dropped before propagation completes (likely a race between mempool insertion and proposer pickup under pipelining). Same family as the other merge-train/spartan pipelining flakes; owner palla is the author of the pipelining migration (#23482, which also migrated this suite).

Test plan

• error_regex: "Tx dropped by P2P node" matches the observed receipt error
• CI continues to run src/composed/web3signer/e2e_multi_validator_node_key_store.test.ts; the P2P-drop failure now alerts palla on #aztec3-ci instead of failing the build

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Created by claudebox · group: slackbot