fix MTU when subnet is using logical gateway

[zhangzujian]

• Make sure you have followed Kube-OVN Code Style.

What type of this PR

• Bug fixes

Which issue(s) this PR fixes:

Fixes #(issue-number)

WHAT

🤖 Generated by Copilot at ccb0800

Improve pod subnet handling for multiple provider networks. Avoid node queries when pod subnet does not use logical gateway in pkg/daemon/handler.go.

🤖 Generated by Copilot at ccb0800

pod subnet checks
if logical gateway is needed
node queries reduced

HOW

🤖 Generated by Copilot at ccb0800

• Add a condition to check pod subnet gateway type (link)
• Skip getting node object if pod subnet does not use logical gateway (link)

[github-actions]

• Priority 1: The condition !podSubnet.Spec.LogicalGateway added to the if statement on line 255 seems to be a new addition. It is important to ensure that this condition does not cause any unintended consequences or break existing functionality. A thorough testing of this change should be done before merging it into the codebase.

• Priority 2: The variable mtu on line 251 is declared but not used anywhere in the function. This could be an indication of unused variables elsewhere in the codebase, which can lead to performance issues and confusion for future developers. It is recommended to remove unused variables to keep the code clean and maintainable.

• Priority 3: The error message on line 259 should be more descriptive and provide more information about the error that occurred. This will help with debugging and troubleshooting in case of errors.

• Priority 4: The variable node on line 257 is declared but not checked for errors. It is important to handle errors properly to avoid unexpected behavior and crashes.

• Priority 5: The indentation on lines 254-256 is inconsistent with the rest of the code. It is recommended to use consistent indentation throughout the codebase to improve readability and maintainability.

[github-actions]

• The condition in line 257 should be refactored to improve readability. It currently has three conditions connected with "&&" which makes it hard to read and understand. Consider breaking it down into separate if statements or using a helper function to make the code more readable.

• The variable name "mtu" in line 255 is not descriptive enough. Consider renaming it to something that better describes its purpose.

• The error message in line 262 should include the original error message for better debugging.

• The error handling in line 267 only logs the error message but does not return an error. Consider returning the error to the caller so that they can handle it appropriately.

• The comments in this file are sparse and could be improved. Consider adding comments to explain the purpose of each function and any complex logic.