Add missing Sphinx extensions and dependencies to requirements.txt

[sanchalitorpe-source]

Description of Changes

This PR adds missing Sphinx extensions and other dependencies used in conf.py to requirements.txt.

These changes ensure that the documentation builds correctly for all contributors.

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Related Issue

Fixes #449

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Type of Change

• ✨ Content Enhancement — Updates or improves existing content

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Additional Notes (Optional)

No additional changes. This PR only updates requirements.txt to include missing Sphinx dependencies.

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Checklist

• I have searched open pull requests to avoid duplicates.
• I have built the book locally using the build instructions and verified my changes work as expected.
• I have written clear, conventional commit messages, as per the Pull Request Guidelines.

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[sanchalitorpe-source]

Hi maintainers 👋

I’ve updated requirements.txt to include all Sphinx extensions that are currently used in conf.py.

I attempted to build the book locally on Windows, but I’m currently blocked by Node.js installation issues.
Since this PR only updates documentation dependencies, I wanted to ask if the current changes are sufficient or if anything else is needed from my side.

Thanks for your time and guidance!