Python images need to support MUSL-based systems (alpine)

[briandealwis]

The python:xx-alpine images require Python debugger packages setup for musl. There doesn't seem to be any image metadata to identify musl/alpine-based images, so skaffold debug can't select a musl-specific image. So this seems to be something that has to be detected at runtime with the new python launcher.

Alpine images:

• /etc/os-release has ID=alpine
• /lib/ld-musl-x86_64.so.1
• /lib/libc.musl-x86_64.so.1
• /lib/libapk.so.3.12.0
• no /lib64

This answer cites existence of /lib/ld-musl-* and /lib/libc.musl-*.