Fix OpenAI tool schema rejection by bumping mcp-go to v0.45.0

[saditya370]

Summary

• Bumps github.com/mark3labs/mcp-go from v0.41.1 to v0.45.0 to fix tool schema serialization
• Parameter-less tools (e.g. users, actions, filters, domains, systems) were serialized as {"type": "object"} — missing the "properties" field that OpenAI's function calling API requires
• Root cause was in the mcp-go library: ToolInputSchema lacked a custom MarshalJSON and used omitempty struct tags, causing Go to silently drop empty "properties" and "required" fields
• Upstream fixes: mcp-go PR #713 added MarshalJSON on ToolInputSchema, mcp-go PR #727 removed omitempty from struct tags

Before:
{"type": "object"}

After:
{"type": "object", "properties": {}, "required": []}

Test plan

• Compiles cleanly with zero breaking API changes
• Verified parameter-less tools now emit "properties": {} and "required": []
• Run mcp-eval/ test suite
• Test against OpenAI function calling API to confirm acceptance

Fixes #14514