docs: Clarify normalization comment re. query watcher

[calvincestari]

Clarification related to #543 (comment).

[svc-apollo-docs]

✅ Docs Preview Ready

Configuration

{
  "repoOverrides": {
    "apollographql/apollo-ios-dev@main": {
      "remote": {
        "owner": "apollographql",
        "repo": "apollo-ios-dev",
        "branch": "docs/clarify-query-watcher-cache-key-normalization"
      }
    }
  }
}

Name	Link
Commit	609b2ff
Preview	https://www.apollographql.com/docs/deploy-preview/873d3fef1706e7f196bb
Build ID	873d3fef1706e7f196bb
File Changes	0 new, 1 changed, 0 removed * (developer-tools)/ios/(latest)/fetching/queries.mdx
Pages	1

---

1 pages published. Build will be available for 30 days.

[netlify]

✅ Deploy Preview for eclectic-pie-88a2ba ready!

Name	Link
🔨 Latest commit	609b2ff
🔍 Latest deploy log	https://app.netlify.com/sites/eclectic-pie-88a2ba/deploys/674110244cd71e0008d00d3e
😎 Deploy Preview	https://deploy-preview-547--eclectic-pie-88a2ba.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.

[netlify]

✅ Deploy Preview for apollo-ios-docc canceled.

Name	Link
🔨 Latest commit	609b2ff
🔍 Latest deploy log	https://app.netlify.com/sites/apollo-ios-docc/deploys/674110243787230008f88e94