woodpecker: add arrproxy-ci service account (#376)

Adds the arrproxy-ci Woodpecker ServiceAccount in the woodpecker namespace so unkin/arrproxy CI pipeline pods (which set serviceAccountName: arrproxy-ci) can run.

Change:
- Add apps/base/woodpecker/serviceaccount_arrproxy_ci.yaml (ServiceAccount arrproxy-ci, namespace woodpecker), mirroring the existing per-repo CI SA pattern (e.g. autobackup-operator-ci, kea-operator-ci).
- Wire it into apps/base/woodpecker/kustomization.yaml resources.

Validation: kustomize build --enable-helm apps/overlays/au-syd1/woodpecker renders cleanly; pre-commit passes.

Unblocks unkin/arrproxy CI.

---------

Co-authored-by: unkin-agent <unkin-agent@git.unkin.net>
Reviewed-on: #376
Co-authored-by: Unkin Agent <unkin-agent@unkin.net>
Co-committed-by: Unkin Agent <unkin-agent@unkin.net>

apps/base/woodpecker/kustomization.yaml

@@ -7,6 +7,7 @@ resources:
   - cnpg_cluster.yaml
   - cnpg_backup.yaml
   - cnpg_pooler.yaml
+  - serviceaccount_arrproxy_ci.yaml
   - serviceaccount_autobackup_operator_ci.yaml
   - serviceaccount_ghp.yaml
   - serviceaccount_kea_operator_ci.yaml

apps/base/woodpecker/serviceaccount_arrproxy_ci.yaml

@@ -0,0 +1,6 @@
+---
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: arrproxy-ci
+  namespace: woodpecker