Php 8.x notice fix on tags & groups fields

[eileenmcnaughton]

#29194 against the rc

While this is not actually a regression the reporter is keen to see it in the ESR and has put some effort into testing it
https://lab.civicrm.org/dev/core/-/issues/4957 so I have put on the rc to keep that option open

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[colemanw]

Merging per testing on the GL issue