feat(simple-workflow): Add secretsEngine support for Sealed Secrets

[schahal]

Related to what was done for other charts as well: #261 (Ideally, simple-workflows would've been added to that as well).

Test

Original values.test.yaml

secretsEngine: plaintext
secrets:
  foo: bar

New values.test.yaml (after generating a sealed secret)

secretsEngine: sealed
secrets:
  foo: 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

Resulting Helm Diff

--- /tmp/orig.yaml	2024-02-28 10:34:01
+++ /tmp/new.yaml	2024-02-28 10:34:56
@@ -2,14 +2,6 @@
 helm dependency update .
 helm template --debug --values values.yaml --values values.test.yaml simple-workflow .
 ---
-# Source: simple-workflow/templates/secret.yaml
-apiVersion: v1
-kind: Secret
-metadata:
-  name: simple-workflow-secrets
-data:
-  FOO: YmFy
----
 # Source: simple-workflow/templates/roles-and-rolebindings.yaml
 apiVersion: rbac.authorization.k8s.io/v1
 kind: Role
@@ -53,6 +45,20 @@
   - kind: ServiceAccount
     name: workflow-service-account
     namespace: simple-workflow
+---
+# Source: simple-workflow/templates/sealedsecret.yaml
+apiVersion: bitnami.com/v1alpha1
+kind: SealedSecret
+metadata:
+  name: simple-workflow-secrets
+  annotations:
+    sealedsecrets.bitnami.com/namespace-wide: "true"
+spec:
+  encryptedData:
+    foo: "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"
+  template:
+    metadata:
+      name: simple-workflow-secrets
 ---
 # Source: simple-workflow/templates/workflow-pipeline.yaml
 apiVersion: argoproj.io/v1alpha1