`preserveBootstrapIgnition` was named after the implementation details in terraform for how to make deleting S3 objects optional. The motivation behind the change was that some customers run installs in subscriptions where policies do not allow deleting s3 objects. They didn't want the install to fail because of that.

With the move from terraform to capi/capa, this is now implemented differently: capa always tries to delete the s3 objects but will ignore any permission errors if `preserveBootstrapIgnition` is set.

We should rename this option so it's clear that the objects will be deleted if there are enough permissions. My suggestion is to name something similar to what's named in CAPA: `allowBestEffortDeleteIgnition`.

Ideally we should deprecate `preserveBootstrapIgnition` in 4.16 and remove it in 4.17.

    4.14+ but I don't think we want to change this for terraform-based installs

    always

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    https://github.com/openshift/installer/pull/7288