update helm chart so it only updates on releases

Author: korewaChino

.github/workflows/helm-oci.yml

@@ -29,6 +29,7 @@ jobs:
     steps:
     - uses: actions/checkout@v2
     - uses: appany/helm-oci-chart-releaser@v0.3.0
+      if: github.event_name == 'push' && contains(github.ref, 'refs/tags/v')
       with:
         name: chisel-operator
         repository: fyralabs/chisel-operator