Expiring and revoking keys is a core part of how OpenPGP is meant to work.
Export just the valid self-sigs:
--export-options parameters
export-minimal
Export the smallest key possible. This removes all
signatures except the most recent self-signature on
each user ID. This option is the same as running
the --edit-key command "minimize" before export
except that the local copy of the key is not modi-
fied. Defaults to no.