Backport "Refine isEffectivelyFinal to avoid no-owner crash" to 3.3 LTS#556

tgodzik merged 2 commits intolts-3.3scala/scala3-lts:lts-3.3from

backport-lts-3.3-23675scala/scala3-lts:backport-lts-3.3-23675Copy head branch name to clipboard