Update Helm release sops-secrets-operator to v0.21.0

Author: renovate[bot]

infra/argo-apps/sops-secret-operator.yaml

@@ -20,7 +20,7 @@ spec:
       source:
         chart: sops-secrets-operator
         repoURL: https://isindir.github.io/sops-secrets-operator
-        targetRevision: 0.20.4
+        targetRevision: 0.21.0
         helm:
           valuesObject:
             secretsAsFiles: