Update alpine version

[Fingolfin69]

Currently, the base Docker image uses alpine:3.15, which includes Python 3.9. However, this version is incompatible with the pysui Python package, which requires at least Python 3.10.

By the way, alpine:3.16 already includes python 3.10 version.

[tdejoigny-ledger]

@Fingolfin69
I understand that it is annoying, but bumping Alpine also involves bumping the toolchain, which is clearly something that requires time and a testing campaign. This cannot be done immediately, even though we are working on moving from Alpine to Debian Slim in 2025.