fix(Validation): Make "mcp_config" optional when using uv

[daemuth]

Motivation and Context

Documentation states that the mcp_server config variable should not be necessary when using uv as a server type.

However, when attempting to compile a manifest without one, compilation failed with the following error message:

ERROR: Manifest validation failed:

  - server.mcp_config: Required

This was due to mcp_config being enforced in the schema for all server types. This PR makes mcp_server optional when the server type is set to uv.

How Has This Been Tested?

This was tested locally by attempting to compile the following manifest.json:

{
  "manifest_version": "0.4",
  "name": "MCP Test",
  "version": "1.0.0",
  "description": "Description",
  "author": {
    "name": "Author"
  },
  "server": {
    "type": "uv",
    "entry_point": "src/server.py"
  },
  "tools": [
    {
      "name": "search_books"
    }
  ],
  "license": "MIT"
}

Breaking Changes

No breaking changes.

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