Use modern A-S functions more cautiously

[andfinally]

Prerequisites (mark completed items with an [x]):

• [x] I have checked that my issue type is not listed here https://github.com/woocommerce/woocommerce/issues/new/choose
• [x] My issue is not a security issue, support request, bug report, enhancement or feature request (Please use the link above if it is).

Issue Description:

WooCommerce 8.8.1 introduced some code dependent on Action Scheduler 3.3+. Under normal circumstances that'd be ok, as this WooCommerce version came with A-S 3.7.0 bundled with it. But other plugins that also bundle A-S may do load an old version of A-S unusually early, preventing the one in WC from loading. (For example WP Mail SMTP 2.8.0 enables its old version of A-S too early for a newer version of A-S to override it.) In this case, activating WooCommerce caused a fatal error like Call to undefined function as_has_scheduled_action, breaking wp-admin.

That immediate issue is being addressed in https://github.com/woocommerce/woocommerce/pull/46630. Other parts of WooCommerce also make calls on as_has_scheduled_action: BatchProcessingController and TransientFilesEngine. The issue seems less urgent there: these other calls do not cause errors which totally break wp-admin. But it may make sense to add some defensive conditions there too.

[barryhughes]

Changing team labels, I think it makes sense for Proton to tackle these. Somewhat related: https://github.com/woocommerce/woocommerce/pull/49243.