All `plugins` tests that require an `ExperimentalDaemon` are migrated
to `integration/plugin/*` and start an experimental daemon to test on
it.
The end goal being to remove the `experimental` build.
Signed-off-by: Vincent Demeester <vincent@sbr.pm>
Upstream-commit: 69bab3832ce1d72dd1d3ed2f2b53143ec9ff102c
Component: engine
