fix(python-servers): cap mcp version below v2.0.0 to prevent startup … - #4645

Description

This PR caps the mcp SDK dependency to <2.0.0 for all Python-based reference servers (fetch, git, and time).

Because the Python MCP SDK recently released version 2.0.0 with breaking changes (renaming McpError to MCPError and removing decorators like @server.list_tools()), unpinned installations like uvx mcp-server-git would resolve the latest 2.0.0 version and instantly crash on startup. Capping the dependencies ensures these servers continue to run properly on older stable SDK APIs.

Server Details

• Server: fetch, git, time
• Changes to: pyproject.toml dependencies

Motivation and Context

This resolves three active startup crash issues:

• Fixes fetch: ImportError on startup with mcp SDK 2.0.0 (McpError renamed to MCPError) #4560 (fetch)
• Fixes time: ImportError on startup with mcp SDK 2.0.0 (McpError renamed to MCPError) #4570 (time)
• Fixes mcp-server-git: Fails to start due to incompatible mcp version #4580 (git)

How Has This Been Tested?

Tested locally by compiling the package and verifying that the dependency resolution caps the mcp SDK below 2.0.0.

Breaking Changes

No (prevents breaking changes introduced by the SDK upgrade).

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 Protocol Documentation
• My changes follows MCP security best practices
• I have tested this with an LLM client
• My code follows the repository's style guidelines
• New and existing tests pass locally