[CHORE]: mcp_eval_server — bump mcp to >=2,<3

[jonpspri]

Summary

After the server has been moved to this repository (tracked in #26), update mcp-servers/python/mcp_eval_server/pyproject.toml to target MCP SDK v2.

Changes required

1. MCP SDK version bump

# Before
mcp>=1.28.1,<2

# After
mcp>=2,<3

2. API changes required by MCP SDK v2

Per the MCP SDK v2 migration guide:

• Protocol type aliases using camelCase have been removed; use snake_case equivalents.
• Review any transport constructor parameters — these may need to move to run()/app call sites.
• Validate that sync handler functions do not call asyncio.get_running_loop().

Acceptance criteria

• mcp constraint updated to >=2,<3 in pyproject.toml
• All tests pass against MCP SDK v2
• CI green

References

• Depends on: [CHORE]: Move output_schema_test_server to mcp-servers/python/output_schema_test_server #26 (move issue)
• MCP SDK v2 migration epic: CF 1.x (x>0) - Support for MCP 2026-07-28 dual-era communication in ContextForge Gateway mcp-context-forge#6218
• Step 10 (mcp-servers update): [CHORE]: MCP SDK v2 — Update mcp-servers subpackages: FastMCP rename, dependency pins (Step 10/11) mcp-context-forge#6228