Find strategy to keep asdf in the develop environment up-to-date

[ericcornelissen]

Relates to #132

Summary

Find a way to keep the asdf version used in the development environment container/image defined for this repository up-to-date. The installation is defined at:

tool-versions-update-action/Containerfile

Line 16 in 90a0613

RUN git clone https://github.com/asdf-vm/asdf.git /.asdf --branch v0.13.1 \

The goal is that this stays pinned to an exact version¹ - for reproducibility - while also staying up-to-date with recent versions semi-automatically - e.g. like Pull Requests by Dependabot.

Footnotes

1. While the fact that git tag refs aren't immutable isn't in scope for this issue, suggestions for how to improve that aspect are welcome. ↩