Flaky test LastValueAggregator

[Flarna]

I have seen the LastValueAggregator failing several times in the past in various PRs. Rerun usually result in a green CI.

I assume this is some timing issue, maybe it's enough to just increase the timeout here.
Usually it's more stable to avoid relying on timeouts instead stub the needed trigger and ensure sequence but I'm not that familiar with metrics SDK.

Log output:

  1) LastValueAggregator
       merge
         return the newly sampled accumulation:

      AssertionError [ERR_ASSERTION]: Expected values to be strictly deep-equal:
+ actual - expected ... Lines skipped

  LastValueAccumulation {
+   _current: 3,
-   _current: 4,
    sampleTime: [
...
      0
    ]
  }
      + expected - actual

       {
      -  "_current": 3
      +  "_current": 4
         "sampleTime": [
           1674779663
           975000000
         ]
      
      at Context.<anonymous> (test\aggregator\LastValue.test.ts:62:14)

see e.g.
https://github.com/open-telemetry/opentelemetry-js/actions/runs/4022668001/jobs/6912651597
https://github.com/open-telemetry/opentelemetry-js/actions/runs/4020374096/jobs/6908235579
https://github.com/open-telemetry/opentelemetry-js/actions/runs/4019619610/jobs/6906675388

[legendecas]

The timeout is used to verify the sample time of the accumulation. It is not supposed to be related to timing issue. I'll take a look at this problem.