Add maxtext tag for DAGs

[RUEI4341]

Description

Add the maxtext tag for DAGs below:

• jax_functional_tests
• multipod_legacy_xlml
• mxla_collective_nightly
• maxtext_gpu_inference

Checklist

Before submitting this PR, please make sure (put X in square brackets):

• I have performed a self-review of my code.
• I have necessary comments in my code, particularly in hard-to-understand areas.
• I have run one-shot tests and provided workload links above if applicable.
• I have made or will make corresponding changes to the doc if needed.

[RUEI4341]

Hi @bvandermoon, @gobbleturk, @RissyRan
Could you please take a look at my PR when you get a chance? Thanks!

[RissyRan]

Wondering what's the criteria for this tag?

I think we have other DAGs that belong to MaxText repo, like

• maxtext_moe_gpu_e2e
• maxtext_moe_tpu_e2e

And those DAGs are MaxDiffusion, but not MaxText?

• maxdiffusion_gpu_e2e
• maxdiffusion_tpu_e2e

[RUEI4341]

Hi @RissyRan,

Thank you for the reminder! You're right — we found that maxdiffusion_gpu_e2e and maxdiffusion_tpu_e2e were incorrectly tagged as MaxText, so we’ve reverted those tag changes.
As for maxtext_moe_gpu_e2e and maxtext_moe_tpu_e2e, they’ve already been correctly tagged.