only apply polyfills where necessary

[Rich-Harris]

ref #7374. i think we tried this once before but had to undo it because of problems with Node 18, but let's give it another go and see what happens with the tests

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[benmccann]

looks like we originally added it here: 7ed3c95#diff-8cae4ccc562be888fea664ae92b47321887907a9d0839c25809da043d6359457

and then removed it here #5292 because of #5292 (comment)

since all the checks are passing I don't see a reason not to merge this