v6.1.0: Link inertia randomization

[stephane-caron]

This release adds link inertia randomization to the Bullet interface contributed by @Tordjx 👍 as well as non-major API updates and a regular batch of fixes.

Added

• Configure pixi in pyproject.toml
• Handle GLIBC version incompatibility in start_simulation.sh
• Spine: Throw an exception when a servo reply has invalid torque
• Update downloaded simulation spine in cache if outdated
• actuation: Added link inertia randomization to the Bullet interface (thanks to @Tordjx)
• actuation: Check maximum torques before sending commands
• cpp: Add ServoError exception
• model: Static model for joints with position, velocity and torque limits
• pixi: Task to generate the documentation by pixi -e docs make

Changed

• CICD: Build release spines with Ubuntu 20.04 rather than 22.04
• CICD: Switch to pixi for documentation workflow
• CICD: Update upload-artifact action to v4
• Remove layout argument to actuation interfaces
• actuation: Rename Interface::initialize_action to Interface::reset_action
• actuation: Rename Interface::servo_joint_map to Interface::servo_name_map
• deps: Upate to palimpsest 2.2.1

Fixed

• examples: Lying genuflection example (thanks to @one-for-all)
• examples: Unwrap environments to get their neutral actions
• Update start_simulation.sh for systems where -v is not defined

Removed

• env: Remove unused leg_return_period and hard-code it to one second
• env: Replace contingent parse_first_observation by a reset override
• model: Remove C++ upkie::model namespace
• observers: Remove upper-leg and wheel joints from configurable parameters

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This discussion was created from the release v6.1.0.