…s preset to s1.nano (#4393)

## What this PR does

Manual backport of #3936 to `release-1.6`.

The automated backport, #4372, pushed conflict markers in
`packages/apps/rabbitmq/README.md` and
`packages/system/rabbitmq-rd/cozyrds/rabbitmq.yaml` as its only commit,
so it would ship them if merged. Both are generated files, and the
conflict is the `tls` block that landed on main after 1.6 was cut.
Everything else applies unchanged, so two differences follow:

- the README parameter table and the cozyrd schema are regenerated from
the 1.6 values with cozyvalues-gen v1.6.0, so they carry the new default
and descriptions without `tls`;
- the 1.6 rabbitmq `Makefile` has no `test` target, so the helm-unittest
sweep would never enter the package and the new preset suite would not
run. The second commit adds the same two lines main already has.

Verified on this branch: the rabbitmq suite passes 4/4, `make -n test`
answers the sweep probe, and a second `make generate` produces no drift.

Change summary, unchanged from #3936: the default `resourcesPreset`
moves from `t1.nano` (128Mi) to `s1.nano` (250m CPU, 512Mi), because a
default-sized RabbitMQ 4.2 broker was OOMKilled on `t1.nano` and never
became Ready. The `resources` and `resourcesPreset` descriptions say the
preset fills every resource `resources` leaves unset.

Close #4372 in favour of this one, or tell me to take a different route
and I will.

### Screenshots

Not a UI change.

### Downstream repositories

Walked the trigger map against the diff: one app chart with a changed
default. The provider follow-up is
cozystack/terraform-provider-cozystack#34, labelled `target/1.7`.

- [ ] No downstream repository is affected by this change
- [ ] [cozystack/website](https://github.com/cozystack/website) -
follow-up:
- [x]
[cozystack/terraform-provider-cozystack](https://github.com/cozystack/terraform-provider-cozystack)
- follow-up: cozystack/terraform-provider-cozystack#34
- [ ]
[cozystack/ansible-cozystack](https://github.com/cozystack/ansible-cozystack)
- follow-up:
- [ ] [cozystack/ccp](https://github.com/cozystack/ccp) - follow-up:
- [ ] [cozystack/talm](https://github.com/cozystack/talm) - follow-up:
- [ ] [cozystack/cozyhr](https://github.com/cozystack/cozyhr) -
follow-up:
- [ ] [cozystack/cozy-proxy](https://github.com/cozystack/cozy-proxy) -
follow-up:
- [ ]
[cozystack/cozystack-telemetry-server](https://github.com/cozystack/cozystack-telemetry-server)
- follow-up:
- [ ]
[cozystack/external-apps-example](https://github.com/cozystack/external-apps-example)
- follow-up:
- [ ] [cozystack/examples](https://github.com/cozystack/examples) -
follow-up:
- [ ] [cozystack/community](https://github.com/cozystack/community) -
follow-up:

### Release note

```release-note
fix(rabbitmq): raise the default resources preset from t1.nano to s1.nano so a default-sized broker is not OOMKilled. Existing brokers that never set resourcesPreset move to s1.nano on upgrade and roll their pods.
```