Let's keep the stable version at the version of the previous release
until we do a new stable release. Unlike the main branch, there's no
need to immediately bump the version to the next version as the only
reason we do that in the main branch is to make sure the version from
the main branch sorts higher than any stable releases for the previous
version. This does not apply for stable releases and so we can safely
keep the old version in meson.version until we do a new stable release.