Track Python SDK and MCP YouTube dependencies with Dependabot #2488

Goal

Track weekly Python dependency updates for the SDK and MCP YouTube server, which the current Dependabot configuration does not cover.

Acceptance criteria

• Add one pip entry for /sdk/python and one uv entry for /docs/knowledge_prototypes/mcp-servers/mcp_youtube-0.2.0, which has pyproject.toml and uv.lock.
• Schedule each weekly with an open pull request limit of 10.
• Preserve the existing root and backend Python entries and avoid duplicate directory entries.
• Add focused tests for the entries, schedules, and limits; verify required checks on the implementing PR.

Implementing PR: #2447.

Correction (2026-10-28): The original criterion called the MCP server entry pip, but that project uses uv.lock; GitHub documents uv as a separate Dependabot ecosystem. The intended outcome is weekly updates to that server’s actual lockfile. See Dependabot options reference.