Use cross to build on x64 for older operating systems

[esafak]

🎯 Feature Summary

x86 builds should use the oldest possible version of glibc to maximize compatibility.

💡 Motivation

I can't use mcp-probe in self-hosted Github runners because they are based on Ubuntu 22 while mcp-probe is built on and requires Ubuntu 24's glibc.

📋 Detailed Description

✅ Acceptance Criteria

• It will be possible to run mcp-probe on x86 operating systems older than Ubuntu 24.

🔧 Implementation Considerations

📖 Documentation Impact

Mention which version of glibc we build against.

🧪 Testing Requirements

We should have tests to ensure

📱 UI/UX Impact

Improved UX, since users of older versions will be included.