Support Wolfi-based dev containers

[imjasonh]

Wolfi is a relatively new distro focused on minimalism and fast package updates, in the service of low-to-no-CVE images. Like Alpine, it uses apk as its package manager. Unlike Alpine, it's glibc-based, and doesn't use musl.

I tried to use devpod to run a Wolfi-based container, and got this error:

Decoding that error, it says:

fetch https://packages.cgr.dev/extras/x86_64/APKINDEX.tar.gz
fetch https://packages.wolfi.dev/os/x86_64/APKINDEX.tar.gz
[https://packages.cgr.dev/extras]
[https://packages.wolfi.dev/os]
OK: 68154 distinct packages available
ERROR: unable to select packages:
 gcompat (no such package):
   required by: world[gcompat]

Looking at the code, it looks like alpine.go expects the presence of apk to determine whether the image is Alpine, and if so, it installs necessary tools, including gcompat. Wolfi, being glibc-based, doesn't include gcompat (it's a glibc compatibility layer for musl), so this fails.

This PR makes the following changes to better support Wolfi-based images:

1. check for the presence of ID=alpine in /etc/os-release to determine if gcompat is needed.
2. rename InstallAlpineRequirements to InstallAPKRequirements and rephrase error messages, since it now handles any distro using apk as a package manager.
3. fix the error message encoding

Let me know if there's anywhere else I should be looking for Alpine assumptions, I'm happy to send more PRs after this one.

[pascalbreuninger]

Hey @imjasonh, thanks a lot for the PR, It's a very welcome fix for Wolfi (I've never tried it personally)!
We should only have this one area where we do a one-off for alpine and it's only because VSCode Server can't install without these dependencies. Other IDEs should be fine.