Long-Term Tracking of Testbed Kubernetes Versions

[XinShuYang]

Describe the problem/challenge you have
Currently, we are using various testbeds such as CAPV, Multicast, Multicluster, VMAgent, Kind, and Windows for Antrea CI pipeline. The Kubernetes versions used in these testbeds may not always align with the latest Kubernetes releases. This misalignment can lead to issues, test failures, or missed opportunities to take advantage of new Kubernetes features.

Describe the solution you'd like
We would like to create a long-term tracking mechanism to keep our testbed Kubernetes versions up to date. This involves the following steps:

• Maintain a record of the current Kubernetes version in use for each testbed.
• Periodically check for new Kubernetes releases.
• Plan and execute the upgrade of Kubernetes versions for each testbed as needed.
• Document the process, any issues encountered, and the outcome.

Anything else you would like to add?
It's essential to maintain our testbeds with the latest Kubernetes versions to align with the Kubernetes releases and to provide the best quality testing for Antrea. This long-term tracking task can help us stay on top of Kubernetes updates and ensure our testing environment remains robust and effective.

Testbed Name	Current Kubernetes Version	Latest Kubernetes Version (if different)
CAPV	v1.28.0	v1.28.3
Multicast	v1.27.2	v1.28.3
Flexible-IPAM	v1.27.1	v1.28.3
Multicluster	v1.27.1	v1.28.3
VMAgent	v1.27.2	v1.28.3
IPv6	v1.27.1	v1.28.3
Windows	v1.28.2(with ginkgo flaky issue)	v1.28.3