Git can be configured to push tags with `push.followTags` but this is
not the default. Pushing the tag explicitly with `git push <remote>
<tag>` is generally considered safer anyways since it only attempts to
push the desired tag.
These haven't been updated in a little while. The original plan was to
update the version (in `Cargo.toml`) after a release to the next
planned release date but the way we release now is to update the version
as a part of the release process (just before tagging). Typically this
is all taken care of in the CHANGELOG-updating branch along with the
other documentation changes like the appdata file. The workflow now is
basically just to merge the changelog/release branch, pull, tag and push.