update opam repository commit to use solo5 0.9 and mirage 4.8.1

[hannesm]

No description provided.

[palainp]

Thank you! While updating things, do you think it's worth updating the debian docker image, debian snapshots, and opam-overlays as well?

[hannesm]

Thank you! While updating things, do you think it's worth updating the
debian docker image

I don't know

debian snapshots,

I don't know

and opam-overlays as well?

there's been no change as far as I can tell.

[palainp]

I don't know neither about the debian ones and I haven't heard anything critical about it, so I'm keen to keep my caches without having to download too many things :)

For opam-overlays, there were lwt_ppx and something about colombe since the current commit hash, but I'm unsure if we need the updates or not.

[hannesm]

we don't ;)

[palainp]

Sorry for the force push, I had to remove the last commit to be able to merge, and I'll reintroduce the updated hashsum value on main.