Github built tarballs have automake issues

[alerque]

For some reason the Github Actions generated release tarballs are missing an automake file. I've posted locally generated ones instead because I've already maee a muck of the last release cycle, but this needs to be reviewed.

[alerque]

For future forensic comparison, here is a Github built artifact (to be compared against the one as posted on the release now, which I built locally): sile-0.10.8.zip.

[alerque]

This might not be GH Actions specific, just different systems have different issues. The GH built one worked fine on Homebrew and Arch Linux last release cycle (v0.10.7), but failed on Nix. The current (v0.10.8) one built my me locally worked fine on Arch and Ubuntu, but failed on Homebrew (see upstream pr).