[pixi] Upgrade dependency versions

[jslee02]

Remove this line and describe this pull request. Link to relevant GitHub issues, if any.

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Before creating a pull request

• Document new methods and classes
• Format new code files using ClangFormat by running make format
• Build with -DDART_TREAT_WARNINGS_AS_ERRORS=ON and resolve all the compile warnings

Before merging a pull request

• Set version target by selecting a milestone on the right side
• Summarize this change in CHANGELOG.md
• Add unit test(s) for this change
• Add Python bindings for new methods and classes

[Copilot]

Pull Request Overview

This PR updates various build and testing dependencies to newer versions to keep the project up to date and benefit from bug fixes and features in the latest releases.

• Bumps build-dependencies versions (benchmark, black, cmake, gtest, isort, pip, pytest, setuptools)
• Maintains < upper bounds to avoid major unexpected upgrades
• Ensures tooling aligns with current project requirements

Comments suppressed due to low confidence (2)

pixi.toml:13

• Upgrading to CMake 4.x can introduce breaking changes; please verify compatibility with CMake 4 or constrain the version if support hasn't been confirmed.

cmake = ">=4.0.2,<5"

pixi.toml:11

• After bumping Black to >=25.1.0, re-run the code formatter to apply any new style rules and ensure the codebase remains consistent.

black = ">=25.1.0,<26"