FEAT(ci): add ArgoCD Image Updater and CI/CD pipelines

- ArgoCD Image Updater for Zot registry polling
- Tekton Tasks: git-clone, buildah-build-push
- Pipelines: nextjs, fastapi, python
- ExternalSecrets for Zot and GitHub credentials

tekton/ci-cd/manifests/kustomization.yaml

@@ -0,0 +1,14 @@
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+
+resources:
+  # Secrets
+  - secrets/zot-registry-secret.yaml
+  - secrets/github-credentials.yaml
+  # Tasks
+  - tasks/git-clone.yaml
+  - tasks/buildah-build-push.yaml
+  # Pipelines
+  - pipelines/nextjs-pipeline.yaml
+  - pipelines/fastapi-pipeline.yaml
+  - pipelines/python-pipeline.yaml