[receiver/k8scluster] Fix e2e tests by limiting jobs/pods of cronjob …

…to 1 (#36235)

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#### Description
Fixes what was described at
#35727 (comment).

After
#36114
the `k8scluster` receiver's e2e tests started showing some flakiness
([example](https://github.com/open-telemetry/opentelemetry-collector-contrib/actions/runs/11701936581/job/32589392145)).

With this change we ensure that only 1 active job/pod of the cronjob
will be present for the whole lifetime of the test to avoid hitting
timing/scheduling related flakiness.

@bacherfl could you also take a look here?

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#### Link to tracking issue
Fixes 

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#### Testing

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#### Documentation

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Signed-off-by: ChrsMark <[email protected]>