fix(argo-cd): only exclude *.tgz in the top-level chart dir (#633)

This should fix #585.
Ref:
- https://github.com/argoproj/argo-helm/issues/585
- https://helm.sh/docs/chart_template_guide/helm_ignore_file/

Signed-off-by: Marco Kilchhofer <mkilchhofer@users.noreply.github.com>

charts/argo-cd/.helmignore

@@ -1,2 +1,2 @@
-*.tgz
+/*.tgz
 output