Fix test retry on throttling

[akashorabek]

Fixes: #34736
Successful run example: https://github.com/akashorabek/beam/actions/runs/14753003019
Updated ThrottlingHandler logic based on the new google-api-core release

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[Abacn]

I see, the cause of breakage is client change, and we relied on non-public implementation detail on throttlng.

Does the change work with old client library?

[Abacn]

Old version failed with

>         self.assertGreater(
              container.get_counter(
                  MetricName('gcsio',
                             "cumulativeThrottlingSeconds")).get_cumulative(),
              1)
E             AssertionError: 0 not greater than 1

We'd need to support both, otherwise this means throttling metrics breaks in google-api-core>=2.25.0rc0

[Abacn]

cc: @shunping

[Abacn]

We can inspect compatible google-api-core version in ThrottlingHandler constructor, then at runtime decide which approach to use to extract throttling time.

[shunping]

Agree！ Let's check the package version before choosing which arg name to access.

I remembered the current approach was the only feasible way to retrieve wait time in an accurate way during my implementation. And I acknowledged it is a bit fragile.

[akashorabek]

Added functionality for dynamic selection of the arg name depending on the version of google-api-core
Successful run example with google-api-core >= 2.25.0rc0 - https://github.com/akashorabek/beam/actions/runs/14795779558
Successful run example with google-api-core < 2.25.0rc0 - https://github.com/akashorabek/beam/actions/runs/14796135246

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[Abacn]

Thank you!