feat: add per-container resource configuration for runner and DinD #160 (#168)

This a correction that is forf from original work of [anders.eficode](https://gitea.com/anders.eficode) on [pull request #160](https://gitea.com/gitea/helm-actions/pulls/160)
Description of the change
Adds statefulset.dind.resources and statefulset.runner.resources as optional per-container resource overrides. When set, each takes precedence over the shared statefulset.resources for that container. When unset (default {}), statefulset.resources is used as before.

Benefits
The DinD sidecar and the runner container have very different resource profiles — DinD is memory-hungry (image layer cache, concurrent builds, image pulls) while the runner is a lightweight coordinator that is mostly idle between jobs. Separate resource limits allow right-sizing each container independently, avoiding the choice between over-provisioning the runner or under-provisioning DinD.

Possible drawbacks
None. Fully backward-compatible — both new values default to {}, causing the shared statefulset.resources fallback to apply exactly as before.

Checklist
- [x] Parameters are documented in the `values.yaml` and added to the `README.md` using [readme-generator-for-helm](https://github.com/bitnami-labs/readme-generator-for-helm)
- [x] Breaking changes are documented in the `README.md`
- [x] Helm templating unittests are added (required when changing anything in `templates` folder)
- [x] Bash unittests are added (required when changing anything in `scripts` folder)
- [x] All added template resources MUST render a namespace in metadata

---------

Co-authored-by: Le Prévost-Corvellec Arnault <arnault.le.prevost.corvellec@carbon-it.com>
Co-authored-by: Anders <lantzanders@gmail.com>
Reviewed-on: https://gitea.com/gitea/helm-actions/pulls/168
Reviewed-by: DaanSelen <135789+daanselen@noreply.gitea.com>
Co-authored-by: Arnault_LPC <194310+arnault_lpc@noreply.gitea.com>

templates/_helpers.tpl

@@ -116,6 +116,13 @@ Create image for the Gitea Actions Act Runner
 {{ include "gitea.actions.common.image" (dict "root" . "image" .Values.statefulset.runner) }}
 {{- end -}}
 
+{{/*
+Resolve resource requests/limits for the runner container.
+*/}}
+{{- define "gitea.actions.runner.resources" -}}
+{{- toYaml (default .Values.statefulset.resources .Values.statefulset.runner.resources) -}}
+{{- end -}}
+
 {{/*
 Create image for DinD
 */}}
@@ -123,6 +130,13 @@ Create image for DinD
 {{ include "gitea.actions.common.image" (dict "root" . "image" .Values.statefulset.dind) }}
 {{- end -}}
 
+{{/*
+Resolve resource requests/limits for the DinD container.
+*/}}
+{{- define "gitea.actions.dind.resources" -}}
+{{- toYaml (default .Values.statefulset.resources .Values.statefulset.dind.resources) -}}
+{{- end -}}
+
 {{/*
 Create image for Init
 */}}