test(ci): mark e2e_expiration_timestamp 'invalidates' race as flake

[AztecBot]

Summary

Adds src/e2e_expiration_timestamp.test.ts to .test_patterns.yml, scoped to the "Block header not found in invalidates-the-transaction setup" error, assigned to @PaLLa.

Caught the merge-train/spartan CI hard-fail in run 26156587222 (log 1779271633316976).

Root cause

Introduced by #23275 (proposer pipelining migration). runInvalidatesTest is called twice (no enqueued public call, then with enqueued public call). The first call's cheatCodes.eth.warp(..., { resetBlockInterval: true }) jumps L1 ~7 minutes ahead; ~800 ms later the archiver's L1-sync poll detects the gap and prunes L2 back to the last checkpointed block. The second call's await aztecNode.getBlockData('latest') races against that prune and briefly returns no header, throwing at line 147.

Sibling enqueuePublicCall=false invocation passes because it runs before the warp.

Scope

The narrow error_regex means only this specific race triggers the flake path; any other failure in e2e_expiration_timestamp.test.ts still hard-fails CI.

Full analysis: https://gist.github.com/AztecBot/e128c4d2b9cdac4925e59e484c8a39b6

Claudebox log: https://claudebox.work/s/428dc488ec96a70f?run=2

ClaudeBox log: https://claudebox.work/s/428dc488ec96a70f?run=2