CI: consider publishing nightly builds via GHCup metadata channel

[ulysses4ever]

GHC is doing it:

• Implement support for nightlies ghcup-hs#824
• https://gitlab.haskell.org/ghc/ghc/-/merge_requests/10373

Quoting ghcup maintainer:

the approach is that you generate a GHCup metadata file every day,
which can be added by the end user just like the pre-release channel

The format is in the types/JSON instances. Or just check the existing metadata
The PR augments the format with two now tags and a release date field

[ulysses4ever]

Related:

• CI: add automated GitHub prereleases #8914
• [META] Regarding the release CI runners: GitHub or the Haskell GitLab? #8674 (not clear if this should be done on github or gitlab)

[hasufell]

Here's an example metadata for GHC: https://gist.github.com/hasufell/ad710e5218969b15b39a1c3eaba2ccfd

The URLs are all fake, but it would look like that. Note the viReleaseDay field.

[ulysses4ever]

@hasufell out of curiosity, what does vi in viReleaseDay stand for?

[hasufell]

@hasufell out of curiosity, what does vi in viReleaseDay stand for?

https://github.com/haskell/ghcup-hs/blob/278a3005d1a45ef3365aa121990dbc61684d7333/lib/GHCup/Types.hs#L137

VersionInfo.