[Backport release-1.6] fix(rabbitmq): right-size the default resources 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 - follow-up:
• cozystack/terraform-provider-cozystack - follow-up: fix(rabbitmq): right-size the default resources_preset to s1.nano terraform-provider-cozystack#34
• cozystack/ansible-cozystack - follow-up:
• cozystack/ccp - follow-up:
• cozystack/talm - follow-up:
• cozystack/cozyhr - follow-up:
• cozystack/cozy-proxy - follow-up:
• cozystack/cozystack-telemetry-server - follow-up:
• cozystack/external-apps-example - follow-up:
• cozystack/examples - follow-up:
• cozystack/community - follow-up:

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.