This makes existing requirements explicit, but doesn't increase them. Due to that, its not really breaking.
Changes
Explicitily fail on startup when systemd version <243
This isn't breaking because v0.17 is already broken for systemd version <243 because the OOMPolicy config set in #101 was [introduced in systemd version 243] (https://github.com/systemd/systemd/commit/afcfaa695cd00b713e7d57e1829da90b692ac6f8) and makes user servers fail to start.
Warn on startup when systemd versions <245
This is motivated by us only testing on systemd version 245.
Add tests against systemd version 245 in Ubuntu 20.04
Version 245 is easy for us to test against, because its part of Ubuntu 20.04. Yuvi suggested testing against the second most newest ubuntu LTS release's systemd version, which is a perfect policy in my mind because of the environments provided by CI systems like GitHub Actions. In GitHub actions, Ubuntu 20.04 and 22.04 is available, but Ubuntu 18.04 isn't available any more and was removed a while after 22.04 had been added.
Summary
This makes existing requirements explicit, but doesn't increase them. Due to that, its not really breaking.
Changes
Related