Fix capd rke2 deployments

What does this MR do and why?

Since we merged !4575 (merged), rke2-coredns is not deployed by default into rke2 based cluster and when flux is trying to deploy unit management-sylva-units in order to trigger sylva-units hr, flux is failing with following error into source controller:

{"level":"error","ts":"2025-06-25T19:16:54.882Z","msg":"Reconciler error","controller":"helmchart","controllerGroup":"source.toolkit.fluxcd.io","controllerKind":"HelmChart","HelmChart":{"name":"sylva-system-sylva-units","namespace":"sylva-system"},"namespace":"sylva-system","name":"sylva-system-sylva-units","reconcileID":"5e39ed7c-d1d1-45dc-be81-94c78d7f8095","error":"chart pull error: failed to download chart for remote reference: failed to get 'oci://registry.gitlab.com/sylva-projects/sylva-core/sylva-units:0.0.0-git-bbbd61e0': failed to do request: Head \"https://registry.gitlab.com/v2/sylva-projects/sylva-core/sylva-units/manifests/0.0.0-git-bbbd61e0\": dial tcp: lookup registry.gitlab.com: i/o timeout"}

Is a normal behavior because once we do not have coredns present on the cluster, pods are not able to preform any dns resolution.

The aim of this MR is to enable coredns via bootstrap values, installing the rke2-coredns on mgmt cluster and overcome this issue.

Related reference(s)

Closes #2564 (closed)

Test coverage

CI configuration

Below you can choose test deployment variants to run in this MR's CI.

Click to open to CI configuration

Legend:

Icon	Meaning	Available values
☁️	Infra Provider	capd, capo, capm3
🚀	Bootstrap Provider	kubeadm (alias kadm), rke2
🐧	Node OS	ubuntu, suse
🛠️	Deployment Options	light-deploy, dev-sources, ha, misc, maxsurge-0, logging, no-logging
🎬	Pipeline Scenarios	Available scenario list and description

• 🎬 preview ☁️ capd 🚀 kadm 🐧 ubuntu

• 🎬 preview ☁️ capo 🚀 rke2 🐧 suse

• 🎬 preview ☁️ capm3 🚀 rke2 🐧 ubuntu

• ☁️ capd 🚀 kadm 🛠️ light-deploy 🐧 ubuntu

• ☁️ capd 🚀 rke2 🛠️ light-deploy 🐧 suse

• ☁️ capo 🚀 rke2 🐧 suse

• ☁️ capo 🚀 kadm 🐧 ubuntu

• ☁️ capo 🚀 rke2 🎬 rolling-update 🛠️ ha 🐧 ubuntu

• ☁️ capo 🚀 kadm 🎬 wkld-k8s-upgrade 🐧 ubuntu

• ☁️ capo 🚀 rke2 🎬 rolling-update-no-wkld 🛠️ ha 🐧 suse

• ☁️ capo 🚀 rke2 🎬 sylva-upgrade-from-1.4.x 🛠️ ha 🐧 ubuntu

• ☁️ capo 🚀 rke2 🎬 sylva-upgrade-from-1.4.x 🛠️ ha,misc 🐧 ubuntu

• ☁️ capo 🚀 rke2 🛠️ ha,misc 🐧 ubuntu

• ☁️ capm3 🚀 rke2 🐧 suse

• ☁️ capm3 🚀 kadm 🐧 ubuntu

• ☁️ capm3 🚀 kadm 🎬 rolling-update-no-wkld 🛠️ ha,misc 🐧 ubuntu

• ☁️ capm3 🚀 rke2 🎬 wkld-k8s-upgrade 🛠️ ha 🐧 suse

• ☁️ capm3 🚀 kadm 🎬 rolling-update 🛠️ ha 🐧 ubuntu

• ☁️ capm3 🚀 rke2 🎬 sylva-upgrade-from-1.4.x 🛠️ ha 🐧 suse

• ☁️ capm3 🚀 rke2 🛠️ misc,ha 🐧 suse

• ☁️ capm3 🚀 rke2 🎬 sylva-upgrade-from-1.4.x 🛠️ ha,misc 🐧 suse

• ☁️ capm3 🚀 kadm 🎬 rolling-update 🛠️ ha 🐧 suse

• ☁️ capm3 🚀 ck8s 🎬 no-wkld 🛠️ light-deploy 🐧 ubuntu

Global config for deployment pipelines

• autorun pipelines
• allow failure on pipelines
• record sylvactl events

Notes:

• Enabling autorun will make deployment pipelines to be run automatically without human interaction
• Disabling allow failure will make deployment pipelines mandatory for pipeline success.
• if both autorun and allow failure are disabled, deployment pipelines will need manual triggering but will be blocking the pipeline

Be aware: after configuration change, pipeline is not triggered automatically. Please run it manually (by clicking the run pipeline button in Pipelines tab) or push new code.