Remove invalid submodule reference to src/mssql-mcp

[olaservo]

Description

I noticed that the package auto publish actions had been logging a warning for a couple weeks. I dug around and found that this submodule was added a couple weeks ago. Its associated to an update PR to the Readme so I'm assuming it was accidental.

Commit which added the submodule: 2ea5d50

Example of action with warning:
https://github.com/modelcontextprotocol/servers/actions/runs/14080538769/job/39432279348#step:18:10

How Has This Been Tested?

Not sure how to test this will actually fix the workflow, open to suggestions.

Breaking Changes

None

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 updated the server's README accordingly
• I have tested this with an LLM client
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have documented all environment variables and configuration options

[olaservo]

Edited description since it looks like the action is still running after this, the fatal is just related to the submodule itself.