test/e2e: remove podman system service tests

Two tests are skipped for a long time because they flaked to much,
nobody cares about them and there are only debugging endpoints mostly so
it is not critical either.

The "of 2 seconds" tests isn't useful either. It waits up to 30s for the
exit so it doesn't actually verify a proper timeout. Additionally we
have similar checks in the system tests "podman system service -
CORS enabled in logs" so I consider this safe to remove.

Fixes containers#12624

Signed-off-by: Paul Holzinger <[email protected]>