sha256 object format has been supported since git 2.29 (~2020), but bitbake cannot fetch those repos. the only thing blocking this seems to be some regular expressions in bitbake (and having new enough git on the host)
For reference a patch was sent on list: https://lore.kernel.org/bitbake-devel/20260618100903.231245-2-mischief@offblast.org/T/#u
looks like this got merged in https://git.openembedded.org/bitbake/commit/?h=master-next&id=707ba7e3f218e9d9fff2649ca4be11e2cf3b45ac.