fix: add Helm chart validation to CI pipeline and fix label indentation

Add helm-lint and helm template validation jobs to PR workflow to catch chart
rendering and YAML syntax errors before deployment. Prevents issues like the
gitlab-ci-default.yaml indentation bug that broke ArgoCD sync.

Also fixes the label indentation in gitlab-ci-default.yaml from 6 spaces to
4 spaces to align with nindent output, resolving YAML parse errors during
Helm template rendering.

This ensures all Helm templates are validated on every PR before merge,
catching deployment issues early in the CI pipeline.

Signed-off-by: Sergiy Kulanov <sergiy_kulanov@epam.com>

Author: SergK

.github/workflows/pr.yaml

@@ -26,3 +26,22 @@ jobs:
 
     - name: "run tests"
       run: make build && make test
+
+  helm-lint:
+    name: Validate Helm chart
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Check out code
+      uses: actions/checkout@v6
+
+    - name: Set up Helm
+      uses: azure/setup-helm@v4
+      with:
+        version: "latest"
+
+    - name: Helm lint
+      run: helm lint deploy-templates
+
+    - name: Helm template
+      run: helm template test deploy-templates > /dev/null

deploy-templates/templates/gitlab/gitlab-ci-default.yaml

@@ -3,8 +3,8 @@ kind: ConfigMap
 metadata:
   name: gitlab-ci-default
   labels:
-      app.edp.epam.com/ci-template: gitlab
-      {{- include "codebase-operator.labels" . | nindent 4 }}
+    app.edp.epam.com/ci-template: gitlab
+    {{- include "codebase-operator.labels" . | nindent 4 }}
 data:
   # Read by krci-portal for template selection UI; not consumed by the operator.
   description: |