Python weather server - Add the ruff llinter and apply it

[a-akimov]

Motivation and Context

Linters help keeping code clean and unified. I've added ruff to the Python server (and then will add to the Python client as well).

When choosing which linting rules to follow, I copied the one that our community is already using for developing the Python SDK (https://github.com/modelcontextprotocol/python-sdk/blob/main/pyproject.toml) to make sure we keep Python projects consistent.

How Has This Been Tested?

Locally.

Breaking Changes

No

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Documentation
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have added or updated documentation as needed

Additional context

N/a