Dev Containers: Update onCreateCommand

[benz0li]

• Update the shell startup files from snippets
• Separate the shell and stack configuration

• Any changes that could be relevant to users have been recorded in ChangeLog.md.
• The documentation has been updated, if necessary

No updates to ChangeLog.md and documentation required.

[mpilgrem]

@benz0li, I merged that.

As an aside, the CI in recent days/weeks has been failing intermittently with:

Stderr:
Pulling image from registry: glcr.b-data.ch/ghc/ghc-musl:9.6.4.
Error response from daemon: Get "https://glcr.b-data.ch/v2/ghc/ghc-musl/manifests/sha256:7f79a0fdca1398c0cc35d0fb1290698430a3cfe26243719cab40189ed29cce60": dial tcp 51.154.68.67:443: i/o timeout
Error: [S-6092]
Could not pull Docker image:
    glcr.b-data.ch/ghc/ghc-musl:9.6.4
There may not be an image on the registry for your resolver's LTS version in
your configuration file.

My assumption is that is either a GitHub glitch or, perhaps, too much demand is being placed on glcr.b-data.ch and it is protesting. Do you have any insight?

[benz0li]

My assumption is that is either a GitHub glitch or, perhaps, too much demand is being placed on glcr.b-data.ch and it is protesting. Do you have any insight?

@mpilgrem There is a rate limit in place. I just increased it.

Let us see if this improves the situation.