Copy cabal fixes from CHaP revisions (#1851)
When making the CHaP release for the previous commit, the CI failure
there revealed that I accidentally changed `>=^0.29` to `>=^0.30`
instead of to `>=0.29 && <0.31` in the `o-c-{cardano,diffusion}`
packages.
I was able to fix that immediately on the CHaP PR view `[[revisions]]`,
so now I'm copying that fix back to this branch to prevent the same
mistake.