Fix pratter 404s

[jmid]

The old pratter repo on GitHub is gone and yields a 404 https://github.com/gabrielhdt/pratter and so does the rev-deps tests, e.g., on #28148:
https://opam.ci.ocaml.org/github/ocaml/opam-repository/commit/c715a95fe87d4397d1f0658b2ae5acd528de705e/variant/compilers,5.3,qcheck-alcotest.0.26,revdeps,pratter.2.0.0

[ERROR] Failed to get sources of pratter.2.0.0: curl error code 404

I failed to find copies on https://github.com/ocaml/opam-source-archives 🤷
Instead I found tagged versions of the old releases on the new location's forge: https://forge.tedomum.net/koizel/pratter/-/tags

On the downside, the new location doesn't offer a .tbz, so I've gone with a tar.bz2 (like the newer non-GitHub-hosted releases) which means that all checksums need updating... 😬
On the upside, all previous versions (except 2.0.0) had a x-commit-hash which matches the commit hash from the new location 😃 🎉

[jmid]

The summary shows

• 2 macOS timeouts
• 2 arg-ergo compilations failing with

- cp -f alt-ergo.opt /usr/local/bin/alt-ergo
- cp: cannot create regular file '/usr/local/bin/alt-ergo': Read-only file system

None of these were caused by changing URLs to non-404 ones and updating the check sums accordingly.

If someone has copies of the .tbz files and prefers that route, I'm fine with it too.
As a last resort we could also just mark the packages as not available 🤷

[mseri]

Before merging this I'd like to check if the packages are available in any of the caches. We tend to not merge if we cannot check that the contents are the same, although there may be a scope for an exception here since there are the commit hashes of those releases

[jmid]

For future reference: What caches are available - and are they publicly accessible?

[mseri]

There are three that I know of and publicly available: https://github.com/ocaml/opam-repository/wiki/FAQ#how-to-find-lost-archives-of-packages

[jmid]

I just found them in Robur's cache ocaml/opam-source-archives#48 ❤️

[jmid]

FTR, the only maintainer action needed here is to merge ocaml/opam-source-archives#48... 🙂

[mseri]

Can you force-push on this with the new urls?

[jmid]

New URLs force pushed - and CI is all green! 🎉

[mseri]

Thanks a lot!