Adapt voxtral_realtime to mistral-common 1.11.5 audio API
Author: juliendenize
Pull request: yes

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# What does this PR do?

Bump mistral-common pin to >=1.11.5:
- Use mistral_common.tokens.tokenizers.audio.Audio and pass base64 audio directly instead of the deprecated RawAudio
- Use get_num_delay_tokens() instead of the deprecated num_delay_tokens attribute
- Call n_right_pad_tokens() (now a method) for the num_right_pad_tokens property
- Online streaming: build the prefill from the low-level audio encoder primitives (start() + encode_streaming_tokens(), get_padding_audio()) instead of passing audio to a TranscriptionRequest, avoiding the deprecation FutureWarning
- Add processing tests covering offline, online streaming, chunked, batched and audio-config-property paths, plus an online-streaming equivalence test

Overall this PR remove future deprecation warnings and clean up a bit the streaming part to avoid doing a hack via an empty TranscriptionRequest.

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## Who can review?

@eustlb @ebezzam @vasqu

Comments:
run-slow: voxtral_realtime

[Workflow Run ⚙️](https://github.com/huggingface/transformers/actions/runs/28383621157)

This comment contains `run-slow`, running the specified jobs: 

models: ["models/voxtral_realtime"]
quantizations: []

## CI Results
[Workflow Run ⚙️](https://github.com/huggingface/transformers/actions/runs/28383621157)

### Commit Info
| Context | Commit | Description |
|---------|--------|-------------|
| RUN | [b7a79285](https://github.com/huggingface/transformers/commit/b7a792859d4a27239be902439b9c91998be6e5d5) | workflow commit (merge commit) |
| PR | [0092dab4](https://github.com/juliendenize/transformers/commit/0092dab471b9bc572842f25718d3a75c9c6bc354) | branch commit (from PR) |
| main | [fdb6d318](https://github.com/huggingface/transformers/commit/fdb6d318138c10ad29ac750388917808f50c867c) | base commit (on `main`) |

### Model CI Report

❌ **[1 new failed tests from this PR](https://huggingface.co/datasets/hf-internal-testing/transformers_pr_ci/raw/f3d86d778777fafbabe9a460b81d885ae25ccedb/2026-06-29/runs/37039-28383621157/ci_results_run_models_gpu/new_failures_with_bad_commit.json)** 😭

- [voxtral_realtime](https://github.com/huggingface/transformers/actions/runs/28383621157/job/84092908492):
    tests/models/voxtral_realtime/test_modeling_voxtral_realtime.py::VoxtralRealtimeForConditionalGenerationIntegrationTest::test_modeling_integration_streaming (✅ ⟹ ❌)



Thanks for adding the test apparently the ci does not pass. The audio feature is a bit change with the refactor but matches what we have internally. I think i'll try tmr to run the same snippet to see if it actually aligns with it !

run-slow: voxtral_realtime

[Workflow Run ⚙️](https://github.com/huggingface/transformers/actions/runs/28405614756)

This comment contains `run-slow`, running the specified jobs: 

models: ["models/voxtral_realtime"]
quantizations: []

## CI Results
[Workflow Run ⚙️](https://github.com/huggingface/transformers/actions/runs/28405614756)

### Commit Info
| Context | Commit | Description |
|---------|--------|-------------|
| RUN | [518df672](https://github.com/huggingface/transformers/commit/518df672b967272cfe2f64d940494342ace6707d) | workflow commit (merge commit) |
| PR | [46920e4f](https://github.com/juliendenize/transformers/commit/46920e4f0788c36367f68d1c0cc66cb3872b5cbb) | branch commit (from PR) |
| main | [957e6032](https://github.com/huggingface/transformers/commit/957e6032a2b5b95ffd885c6ab9f114976eb895cb) | base commit (on `main`) |

✅ No failing test specific to this PR 🎉 👏 !


The introduced failing slow test was only compute-related (A100 vs A10G), all green now. 
pinging also a core maintainer here since we're touching `setup.py` cc @vasqu 🙏

The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/transformers/pr_46920). All of your documentation changes will be reflected on that endpoint. The docs are available until 30 days after the last update.

Thanks for the review and the help ! tried to merge main but i think i cannot be last writer to launch the ci due to changing setup.py :/ 

Yep, no worries, manually approved CI to run

nice ty ! i think the ci test failing is unrelated :smile:

Yep working on it in #47064, will merge after we have resolved that :saluting_face: 

Unrelated failure again I'm so sorry, will merge by today in any case. Sorry about all this :cry: 

Thank you for your contribution 🤗!

## CI Security Gate — automatic approval blocked

This PR was **not** automatically approved for CI because the security gate failed.

**Possible reasons:**
- The PR touches 50 or more files — only PRs with fewer than 50 changed files are automatically approved
- A changed file is outside the allowed directories (`src/`, `tests/`, `docs/`, `utils/`), has a disallowed extension (only `.py`, `.txt`, `.md` permitted outside `tests/` and `docs/`), or is not `.md`/`.yml` inside `docs/`
- A new high-severity security issue was detected in the changed Python files (Bandit check)

See the [workflow run](https://github.com/huggingface/transformers/actions/runs/28878257119) for the exact violations.

A maintainer can review and manually approve CI if a finding is a false positive.

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

run-slow: voxtral_realtime

<!-- ci-dashboard-recap:start -->

---

### CI recap

**Dashboard:** [View test results in Grafana](https://transformers-ci.lor-e.huggingface.cool/d/pytest-observability-by-pr/pytest-observability-branch?var-pr=46920)
**Latest run:** [28878260316:2](https://github.com/huggingface/transformers/actions/runs/28878260316)
**Result:** `success` | **Jobs:** 15 | **Tests:** 172,741 | **Failures:** 0 | **Duration:** 21h 6m

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Another flaky test, merged it because it got too annoying :sweat: and I didnt want to delay further