Add benchmark-specific pip installation option

[bvandermoon]

Description

Add a new installation option for users to build Docker images, run XPK, and use the benchmark runner. These features require a lot fewer dependencies than running MaxText commands, so a separate installation option makes sense.

The new generated requirements file was created with seed-env:

seed-env \
    --local-requirements=src/dependencies/requirements/base_requirements/benchmarks-requirements.txt \
    --host-name=MaxText \
    --python-version=3.12 \
    --requirements-txt=benchmarks-requirements.txt \
    --output-dir=generated_tpu_artifacts

Tests

uv pip install -e .[benchmarks] --resolution=lowest

docker_build_dependency_image

python3 -m benchmarks.benchmark_runner xpk \
    --project=$PROJECT \
    --zone=$ZONE \
    --device_type=v6e-256 \
    --num_slices=1 \
    --cluster_name=${CLUSTER_NAME} \
    --base_output_directory=${OUTPUT_DIR} \
    --model_name="llama3_1_70b_8192" \
    --base_docker_image=maxtext_base_image

Checklist

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• I have performed a self-review of my code. For an optional AI review, add the gemini-review label.
• I have necessary comments in my code, particularly in hard-to-understand areas.
• I have run end-to-end tests tests and provided workload links above if applicable.
• I have made or will make corresponding changes to the doc if needed, including adding new documentation pages to the relevant Table of Contents (toctree directive) as explained in our documentation.

[codecov]

Codecov Report

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