improve Alpine 3.17 helix image

[wfurt]

This is follow-up on #792 and #797

While #792 improved runtime test runs, some were still failing - particularly parsing foreign numbers.
It seems like musl-locales package adds the missing definition (and locale -a work now just like glibc)

#797 added base 3.17 image. So I refactor this to use it as base instead of duplicating the package.
While helix may not need all the dev tools this is the structure we used in previous releases.
Investigation if we can string helix images would be probably separate effort.

[wtgodbe]

Looks like we only have the helix dockerfile for 3.16, is just adding musl-locales sufficient there? I can make that change in #798

[wfurt]

Looks like we only have the helix dockerfile for 3.16, is just adding musl-locales sufficient there? I can make that change in #798

yes, I think just adding the package should be sufficient. I'm going to run full runtime tests and I can comment on #798 when I know the results.