[harshaljanjani]

What does this PR do?

The following failing Dia use case was identified and fixed in this PR:

→ MIGRATION_GUIDE_V5.md states that v5 renamed additional_special_tokens to extra_special_tokens internally as part of the tokenizer refactor; but tokenization_mluke.py (amongst other instances) still references self.additional_special_tokens_ids, which is the only remaining call site under the old name that needs fixing :)
→ For more details on reproducing the bug and the output screenshots, please visit the linked issue!

Fixes #44361.

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[github-actions]

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

run-slow: mluke

[Rocketknight1]

Yeah, this looks like it was just missed in the migration. Thank you!

[HuggingFaceDocBuilderDev]

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