Add bitwarden HELLO_WORLD item to eclipse-pass for secret retrieval

Based on
https://gitlab.eclipse.org/eclipsefdn/security/otterdog#bitwarden

We want to store the credentials like

```
"organizations": [
  {
    "name": "<org name>",
    "github_id": "<github org id>",
    "credentials": {
      "provider": "bitwarden",
      "item_id" : "<bitwarden item id>"
    }
  }
]
```

Two problems I believe

1) I think `credentials` should be a list, not an object, so

```
"organizations": [
  {
    "name": "<org name>",
    "github_id": "<github org id>",
    "credentials": [{
      "provider": "bitwarden",
      "item_id" : "<bitwarden item id>"
    }]
  }
]
```

and

2) I think we should add via jsonnet, so more like

```
orgs.newOrg('eclipse-pass') {
  credentials+: [{
      "provider": "bitwarden",
      "item_id" : "23801ca4-fd27-446c-b5af-b07b0108f443"
    },
  ],
}
```

otterdog/eclipse-pass.jsonnet

@@ -17,6 +17,11 @@ orgs.newOrg('eclipse-pass') {
       default_workflow_permissions: "write",
     },
   },
+  credentials+: [{
+      "provider": "bitwarden",
+      "item_id" : "23801ca4-fd27-446c-b5af-b07b0108f443"
+    },
+  ],
   secrets+: [
     orgs.newOrgSecret('GH_PAT') {
       value: "********",