fix: Correctly register and deregister terminating kernels

[fregataa]

Agent registers kernel ids to its terminating_kernels so that it can track kernels under "terminate" lifecycle.
There are some holes that kernel ids cannot be deleted from the terminating_kernels, which block destroying or cleaning the kernels by sync_container_lifecycle task.

Checklist: (if applicable)

• Milestone metadata specifying the target backport version

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[fregataa]

Continue this work on #2178 , close this PR