[lorenzozanee]

What does this PR do?

Fixes #48080

ZambaMambaMixer hard-coded use_associative_scan=False, so ZambaConfig could not control whether torch.compile used the associative-scan path.

This adds use_associative_scan to ZambaConfig (default True, matching MambaConfig) and forwards it from the mixer instead of the hard-coded value. The associative-scan branch only runs while torch.compile is tracing (is_torchdynamo_compiling()), so eager execution is unchanged. A regression test in tests/models/zamba/test_modeling_zamba.py pins that the configured value reaches mamba_selective_scan.

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• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
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• Did you write any new necessary tests?

Who can review?

@ArthurZucker
@Cyrilvallez
@albertvillanova

Code Agent Policy

• (First-time contributors only): I confirm that this PR description and code is not written by an LLM or code agent

[github-actions]

[For maintainers] Suggested jobs to run (before merge)

run-slow: zamba

[github-actions]

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CI recap

Dashboard: View test results in Grafana
Latest run: 33576824417
Result: success | Grafana metrics are not available yet.

[Cyrilvallez]

cc @vasqu here as well, but I don't think we want to re-add this kind of stuff do we?

[vasqu]

I swear I have seen another one of those PR and it failed on the test not being properly done. I already flagged that reviews on this might get delayed as its low prio

Tbh, it's ok to add and I was probably to lazy at the time of the refactor. It's a free win on perf using the same tricks as in mamba1

@lorenzozanee if you are still up for it I'd review but would like a response first before investing time here

[ArthurZucker]

Thanks @lorenzozanee! use_associative_scan was added to ZambaConfig in #48331, so closing.