Switch to uv for pipelines

[kwsantiago]

Closes #567

Summary

• Replace poetry with uv in GitLab pipeline for gl-client-py publishing
• Remove poetry installation from gl-testing Dockerfile
• Update GitHub docs workflow to use uv exclusively
• Remove all poetry.lock files and convert poetry configurations to standard pyproject.toml format
• Update documentation to reference uv instead of poetry

Changes

• GitLab pipeline: Updated gitlab/build-pypi.yml to use uv run maturin commands
• Docker: Removed poetry installation from docker/gl-testing/Dockerfile
• GitHub workflow: Removed poetry installation step from .github/workflows/docs-action.yml
• Python example: Converted examples/python/pyproject.toml from poetry to standard format
• Documentation: Updated docs/README.md and docs/src/tutorials/testing.md to use uv commands
• Cleanup: Removed poetry.lock files from repository

All Python package management now uses uv consistently across the project.