docs: note merge-train/spartan-v6 → v6-next in the base-branch table

[AztecBot]

Documents the new v6 release line in the CLAUDE.md git-workflow base-branch guidance, so contributors and agents pick merge-train/spartan-v6 (→ v6-next) for v6 work instead of defaulting to merge-train/spartan or next. Mirrors the existing spartan-v5 → v5-next note.

-For work scoped to the v5 release line, use `merge-train/spartan-v5` (which targets `v5-next`) in place of `merge-train/spartan`.
+For work scoped to a release line, use the matching `merge-train/spartan-v<N>` … `spartan-v5` targets `v5-next`, and `spartan-v6` targets `v6-next` (the public staging line for v6 work).

Doc-only. Companion to the merged v6 merge-train wiring (#24516 / #24517) and label generalization (#24538 / #24539).

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Created by claudebox · group: slackbot

[AztecBot]

Flakey Tests

🤖 says: This CI run detected 1 tests that failed, but were tolerated due to a .test_patterns.yml entry.

\033FLAKED\033 (8;;http://ci.aztec-labs.com/2c20fa72d2bee5ea�2c20fa72d2bee5ea8;;�):  yarn-project/end-to-end/scripts/run_test.sh simple src/e2e_epochs/epochs_invalidate_block.parallel.test.ts "proposer invalidates multiple checkpoints" (429s) (code: 0) group:e2e-p2p-epoch-flakes