fix: Unique constraint should account for soft deleted records (#11048)

FIXES FRMW-2878

**What**
Currently, the `one-to-one` unique constraints does not account for deleted record. This prevents from inserting a new record wth the same fk if another one is deleted.

**Caveat**
`hasOne` with FK option is meant to be a special case, for example a many to one - one to many without defining the other side of the relation. In that case we don't handle this behaviour and keep it as it is

packages/modules/workflow-engine-redis/src/models/workflow-execution.ts

@@ -23,6 +23,11 @@ export const WorkflowExecution = model
       on: ["transaction_id"],
       where: "deleted_at IS NULL",
     },
+    {
+      on: ["workflow_id", "transaction_id"],
+      unique: true,
+      where: "deleted_at IS NULL",
+    },
     {
       on: ["state"],
       where: "deleted_at IS NULL",