refactor: rename chart to charts [ci skip]

it is common practice to name the folder charts even though there is only one helm chart

.gitlab-ci.yml

@@ -22,6 +22,6 @@ deploy:prod:
   environment:
     name: prod
   script:
-    - helm upgrade --install wsj-standup ./deploy/chart/wsj-standup --namespace wsj --set image.tag=$IMAGE_TAG --set=app.WEBHOOK_URL=$DISCORD_WEBHOOK_URL --set app.SENTRY_DSN=$SENTRY_DSN --set image.pullSecretBase64=$REGISTRY_PULL_SECRET_BASE64
+    - helm upgrade --install wsj-standup ./deploy/charts/wsj-standup --namespace wsj --set image.tag=$IMAGE_TAG --set=app.WEBHOOK_URL=$DISCORD_WEBHOOK_URL --set app.SENTRY_DSN=$SENTRY_DSN --set image.pullSecretBase64=$REGISTRY_PULL_SECRET_BASE64
   rules:
     - if: '$CI_COMMIT_BRANCH == "main"'