Fix resource leak in PortAllocator canBind method

[hoteye]

Summary

Fixed a potential resource leak in the canBind method of PortAllocator class.

Problem

The original implementation manually created and closed ServerSocket instances, which could lead to resource leaks if an exception occurred between socket creation and the explicit close() call.

// Original code with potential leak
try {
    ServerSocket socket = new ServerSocket(port);
    socket.close();  // If exception thrown here, socket won't be closed
    return true;
} catch (IOException exception) {
    return false;
}

Solution

Replaced manual resource management with try-with-resources statement to ensure automatic cleanup:

// Fixed code with automatic resource management
try (ServerSocket socket = new ServerSocket(port)) {
    return true;  // Socket automatically closed regardless of outcome
} catch (IOException exception) {
    return false;
}

Benefits

• Prevents resource leaks: Socket handles are guaranteed to be released
• Cleaner code: Removes manual resource management boilerplate
• Exception safety: Resources cleaned up even if unexpected exceptions occur

Test plan

• Verified code compiles without errors
• Confirmed try-with-resources follows Java best practices
• No functional changes to the method behavior

[laurit]

I'm fine with this change, but there really is no resource leak in the original code. Since there is no code between opening and closing the socket there isn't anything that could throw an exception an prevent close from running.

[hoteye]

@laurit Thank you for your thoughtful review and clear explanation!