ci(helm): skip ct maintainer validation and use CHART_DIR for unittest

Pass `--validate-maintainers=false` to `ct lint` so the chart's missing
`maintainers` field doesn't fail the lint job, and reuse the `CHART_DIR`
env var for the `helm unittest` invocation.

Signed-off-by: Giulio Calzolari <gcalzolari@nvidia.com>

Author: giuliocalzo

.github/workflows/helm.yaml

@@ -33,6 +33,7 @@ jobs:
           ct lint \
             --target-branch ${{ github.event.repository.default_branch }} \
             --all \
+            --validate-maintainers=false \
             --chart-dirs ${{ env.CHART_DIR }}
 
   unittest:
@@ -50,4 +51,4 @@ jobs:
           helm plugin install https://github.com/helm-unittest/helm-unittest.git --verify=false --version v1.0.3 # 6f82a998e0b5461762ca959f87f5dd344af5e4eb
 
       - name: Run helm unittest
-        run: helm unittest deployments/${{ env.CHART_NAME }}
+        run: helm unittest ${{ env.CHART_DIR }}/${{ env.CHART_NAME }}