Fix(setup.sh): Correct path to extra_deps_from_github.txt

[AidenYu1673]

Description

What does this PR do?
This PR fixes a bug in setup.sh that causes the script to fail with a "File not found" error when trying to install extra_deps_from_github.txt.

Why is this change necessary?
The path used in the uv pip install command (${MAXTEXT_REPO_ROOT}/extra_deps_from_github.txt) is incorrect. After the major repository refactor that moved project code into the src/ directory, the correct location for this file is now ${MAXTEXT_REPO_ROOT}/src/install_maxtext_extra_deps/extra_deps_from_github.txt.

How does this PR fix the issue?
This PR updates the uv pip install command in setup.sh to point to the correct file path.

Before:

... -r "${MAXTEXT_REPO_ROOT?}"'/extra_deps_from_github.txt'

After:

... -r "${MAXTEXT_REPO_ROOT?}"'/src/install_maxtext_extra_deps/extra_deps_from_github.txt'

FIXES: b/454233010

Checklist

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

• 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.

[bvandermoon]

@SamuelMarks are these changes already in #2541?

[SamuelMarks]

@bvandermoon Yes