docs: Removed the mention of the slack MCP server since it was removed

MCP-Servers.md

@@ -247,7 +247,6 @@ Coyote ships with a `functions/mcp.json` file that includes some useful MCP serv
 * [atlassian](https://github.com/atlassian/atlassian-mcp-server) - Interact with and manage Atlassian tools like Confluence and Jira.
 * [github](https://github.com/github/github-mcp-server) - Interact with GitHub repositories, issues, pull requests, and more.
 * [docker](https://github.com/ckreiling/mcp-server-docker) - Manage your local Docker containers with natural language
-* [slack](https://github.com/korotovsky/slack-mcp-server) - Interact with Slack
 * [ddg-search](https://github.com/nickclyde/duckduckgo-mcp-server) - Perform web searches with the DuckDuckGo search engine
 * [iwe](https://github.com/iwe-org/iwe) - Navigate and manage large markdown knowledgebases (plan repos, specs, notes) as a structured
   graph. The server is rooted at the directory Coyote is launched from (`--project .`), runs fully locally (no network access needed),