fix(testing): Fix Kyutai Speech-To-Text, LLaVA-OneVision, and LongCatFlash test failures on main CI

[harshaljanjani]

What does this PR do?

The following failing tests were identified and fixed in this PR:

→ Kyutai Speech-To-Text: The PR [processors] Unbloating simple processors, refactored ProcessorMixin.call to use explicit keyword-only params instead of accepting positional arguments; but the KyutaiSTT integration tests were still calling processor(samples) positionally; the audio samples in the current state mapped to the images param.
→ LLaVA-OneVision: The PR Load a tiny video to make CI faster introduced local video file path mappings. LlavaOnevision's setUpClass was still building paths to Big_Buck_Bunny_720_10s_10MB.mp4 and sample_demo_1.mp4 in the repo root.
→ LongCatFlash: The PR [V5] Return a BatchEncoding dict from apply_chat_template by default again changed apply_chat_template to return BatchEncoding dict instead of a tensor. The test was passing this dict directly to model.generate and tried to access .shape on the dict; this fixes that :)

Note: The test still fails with an AssertionError, I'm not too sure and it could be flaky, but the crash should be resolved :)

cc: @Rocketknight1 @zucchini-nlp

CI Failures

Before the fix (feel free to cross-check; these errors are reproducible):

After the fix (feel free to cross-check):

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[github-actions]

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

run-slow: kyutai_speech_to_text, llava_onevision, longcat_flash