cardano-ledger-byron depends on non-existent "cardano-ledger"

[tchoutri]

While implementing support for #909 I observed that cardano-ledger-byron depends on non-existent cardano-ledger: https://github.com/IntersectMBO/cardano-ledger/blob/a9e78ae63cf8870f0ce6ce76bd7029b82ddb47e1/eras/byron/ledger/impl/cardano-ledger-byron.cabal#L403C5-L403C19

I cannot find this particular package in https://chap.intersectmbo.org/all-packages, which is breaking the now more fragile but more precise package import job.

cc @angerman @fraser-iohk Can you advise on how to behave in such situations? I thought that Cardano packages were systematically uploaded into CHaP.