LangChain4j Agent MCP tests do not run properly on GitHub Windows runner

[jamesnetherton]

Follow up from #8001.

There's something odd happening on the GitHub Windows runner with Langchain4jAgentTest.agentWithMcpClient. On a local Windows 11 machine, the test passes fine:

The server-everything process is started and produces messages:

[dev.langchain4j.mcp.client.transport.stdio.StdioMcpTransport] (main) Starting process: [npx.cmd, -y, @modelcontextprotocol/server-everything]
[dev.langchain4j.mcp.client.transport.stdio.StdioMcpTransport] (main) PID of the started process: 1480
[MCP] (main) > {"jsonrpc":"2.0","id":0,"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{"roots":{"listChanged":true}},"clientInfo":{"name":"langchain4j","version":"1.0"}}}
[dev.langchain4j.mcp.client.transport.stdio.ProcessStderrHandler] (Thread-31) [ERROR] Starting default (STDIO) server...
[dev.langchain4j.mcp.client.transport.stdio.ProcessStderrHandler] (Thread-31) [ERROR] Starting logs update interval

On GitHub Actions, the process is apparently started, but it doesn't seem to do anything:

DEBUG [dev.langchain4j.mcp.client.transport.stdio.StdioMcpTransport] (main) Starting process: [npx.cmd, -y, @modelcontextprotocol/server-everything]
DEBUG [dev.langchain4j.mcp.client.transport.stdio.StdioMcpTransport] (main) PID of the started process: 1296
[MCP] (main) > {"jsonrpc":"2.0","id":0,"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{"roots":{"listChanged":true}},"clientInfo":{"name":"langchain4j","version":"1.0"}}}