The createViewlessTimeseriesFeature enables FCV upgrade/downgrade logic that transforms existing time-series collections between viewful and viewless formats. During these DDL transformations, concurrent CRUD operations can fail with InterruptedDueToTimeseriesUpgradeDowngrade. As a result, we cannot safely run time-series tests in the simpler FCV upgrade/downgrade suites, since they would frequently fail with this error.

To address this, we want to add a new suite, fcv_upgrade_downgrade_retryable_writes_replica_sets_jscore_passthrough, where we can safely run time-series tests. In this suite, write operations that fail with InterruptedDueToTimeseriesUpgradeDowngrade will be retried.

Recap:

• fcv_upgrade_downgrade_replica_sets_jscore_passthrough: already exists, but we cannot run time-series tests in it due to InterruptedDueToTimeseriesUpgradeDowngrade failures.
• fcv_upgrade_downgrade_primary_step_down_passthrough: already exists, but most time-series tests are skipped because they are tagged with does_not_support_stepdowns.
• fcv_upgrade_downgrade_retryable_writes_replica_sets_jscore_passthrough: this ticket adds this new suite, where time-series tests can run and write operations interrupted by time-series upgrade/downgrade will be retried.