Cleanup: Remove unused lastContainerStartedTime time.Cache lru

[azylinski]

What type of PR is this?

/kind cleanup

What this PR does / why we need it:

On Jul 21, 2020 @liggitt added "Ensure runtimeCache contains all observed started containers on pod delete": change

On Jul 9, 2021 main part of this functionality was replaced: change , but the lastContainerStartedTime cache left.

The lru cache is being populated and updated, but it's no longer read from.
As a result, since v1.22 onwards, we're building a latest containerStarted events log which is unnecessary.
And, IMHO, it could/should be removed.

Does this PR introduce a user-facing change?

NONE

[k8s-ci-robot]

Please note that we're already in Test Freeze for the release-1.25 branch. This means every merged PR will be automatically fast-forwarded via the periodic ci-fast-forward job to the release branch of the upcoming v1.25.0 release.

Fast forwards are scheduled to happen every 6 hours, whereas the most recent run was: Fri Aug 19 07:42:40 UTC 2022.

[pacoxu]

/release-note-none
/priority backlog
/triage accepted

[pacoxu]

/release-note-none
/priority backlog
/triage accepted

[pacoxu]

/lgtm
since dab6f6a#diff-67dd9e8f3ee257072765326cb4f242852554a2c0753563fa51e292c0a63a7b94L1801-L1805 was removed.

/assign @liggitt @smarterclayton

[liggitt]

/lgtm
/approve

[k8s-ci-robot]

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This pull-request has been approved by: azylinski, liggitt

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