I'm confused about what the term "ltsrel" means. The way I understand it,
it *should* mean that the extension supports only Long Term Support
versions of MediaWiki. It would have a branch for every LTS version of
MediaWiki like REL1_31 and REL1_35, but not for REL1_32, REL1_33 or REL1_34.
However, on the Compatibility
<https://www.mediawiki.org/wiki/Compatibility#MediaWiki_extensions> page,
the rel and ltsrel policies are described as:
* release branches (key: rel): For every MediaWiki release, there is a
corresponding branch in the extension. So e.g. if you use MediaWiki 1.36,
you should use the REL1_36 branch of the extension.
* long-term support release branches (key: ltsrel): For every MediaWiki
release, there is a corresponding branch in the extension, following the
Version lifecycle release policy.
These sound exactly alike to me.