I guess removing rand_distr has caused the minimal version of serde_derive to go from 1.0.157 to 1.0.103 which causes the CI failure

Looks good.

The minimal-dependency-version test isn't much use then, is it? But some people want it (unless it's fallen out of fashion; I haven't heard much about this for a while).

Should we require a newer version of serde, if 1.0.103 is not working correctly?

Do we need utils/redirect.html? The ziggurat tables should probably only be in rand_distr.

Should there be a changelog entry? If yes where?

Looks good.

The minimal-dependency-version test isn't much use then, is it? But some people want it (unless it's fallen out of fashion; I haven't heard much about this for a while).

It was actually serde_json which is only a dev dependency. So I have bumped the version.

I think it is still sensible to check if the minimal version requirements work. For us having different crates in the same workspace leads to false negatives on it as we have seen here.

Do we need utils/redirect.html?

Yes (it's used by gh-pages.yml).

Should there be a changelog entry? If yes where?

No; it's not a change to any crate.