docs: Use ubuntu-slim runner image

[xavier2k6]

• Use ubuntu-slim runner image for docs workflow

From https://docs.github.com/en/actions/reference/runners/github-hosted-runners#single-cpu-runners :

This type of runner is optimized for automation tasks, issue operations and short-running jobs. They are not suitable for typical heavyweight CI/CD builds.

• https://github.com/actions/runner-images?tab=readme-ov-file#available-images
• https://github.com/actions/runner-images/blob/main/images/ubuntu-slim/ubuntu-slim-Readme.md
• https://docs.github.com/en/actions/reference/runners/github-hosted-runners#standard-github-hosted-runners-for-public-repositories

[arvidn]

the failure is odd. "Umeå" is present in the libtorrent.dic file. Perhaps there's some UTF-8 feature omitted in the slim runner.

[xavier2k6]

the failure is odd. "Umeå" is present in the libtorrent.dic file. Perhaps there's some UTF-8 feature omitted in the slim runner.

This runner image is new enough, so may need to hold off on using it in this repo until more details can be provided in relation to installed software/dependencies & limitations..

[xavier2k6]

bsdextrautils is currently not included in the ubuntu-slim image, unsure if it's related.