Translate hyphens to underscores.

This only matters when testing with pre-releases. We expect our
`PKGBUILD` to translate back[^1] when fetching sources.

[^1]: https://wiki.archlinux.org/title/PKGBUILD#pkgver

Author: pbrisbin

.github/actions/aur-publish/entrypoint.sh

@@ -33,7 +33,7 @@ cd "$PKGNAME"
 echo "::endgroup::"
 
 echo "::group::Update PKGBUILD and .SRCINFO"
-sed -i 's/^pkgver=.*$/pkgver='"$PKGVER/" PKGBUILD
+sed -i 's/^pkgver=.*$/pkgver='"${PKGVER//-/_}/" PKGBUILD
 sed -i 's/^pkgrel=.*$/pkgrel=1/' PKGBUILD
 updpkgsums
 makepkg --printsrcinfo >.SRCINFO