update dev container to 3.14

[wmalgadey]

Proposed Changes

This PR upgrades the development environment and library from Python 3.12 to Python 3.14, fixes the DevContainer startup, and updates several dependencies to versions that provide Python 3.14 wheel support.

Changes:

• Upgraded Python requirement to 3.14 across pyproject.toml, uv.lock, DevContainer, all GitHub Actions workflows, and sonar-project.properties.
• Fixed DevContainer startup by switching updateContentCommand to postStartCommand, replacing POETRY_VIRTUALENVS_IN_PROJECT with UV_PROJECT_ENVIRONMENT, and correcting interpreter paths to use ${workspaceFolder}.
• Updated multiple dev dependencies to newer versions (pytest 9.x, pytest-asyncio 1.x, ruff 0.15.x, deptry 0.24.x, orjson 3.11.x, syrupy 5.x, prek 0.3.4) and loosened version pinning from == to >=.

Related Issues

relates to #138, #134, #137

[erwindouna]

Looks good and even some more stuff added, thanks @wmalgadey!