chore(deps): update actions/cache action to v5 (#13146)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [actions/cache](https://redirect.github.com/actions/cache) | action |
major | `v4` → `v5` |

---

### Release Notes

<details>
<summary>actions/cache (actions/cache)</summary>

### [`v5`](https://redirect.github.com/actions/cache/compare/v4...v5)

[Compare
Source](https://redirect.github.com/actions/cache/compare/v4...v5)

</details>

---

### Configuration

📅 **Schedule**: Branch creation - "every weekend" in timezone
America/Los_Angeles, Automerge - At any time (no schedule defined).

🚦 **Automerge**: Disabled by config. Please merge this manually once you
are satisfied.

♻ **Rebasing**: Whenever PR is behind base branch, or you tick the
rebase/retry checkbox.

🔕 **Ignore**: Close this PR and you won't be reminded about this update
again.

---

- [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check
this box

---

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View the [repository job
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.github/workflows/copilot-setup-steps.yml

@@ -42,7 +42,7 @@ jobs:
 
       - name: Cache downloaded skills and instructions
         id: cache-skills
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: |
             .agents/skills/apollo-client/

.size-limits.json

@@ -1,6 +1,6 @@
 {
-  "import { ApolloClient, InMemoryCache, HttpLink } from \"@apollo/client\" (CJS)": 46900,
-  "import { ApolloClient, InMemoryCache, HttpLink } from \"@apollo/client\" (production) (CJS)": 41576,
-  "import { ApolloClient, InMemoryCache, HttpLink } from \"@apollo/client\"": 35524,
-  "import { ApolloClient, InMemoryCache, HttpLink } from \"@apollo/client\" (production)": 29299
+  "import { ApolloClient, InMemoryCache, HttpLink } from \"@apollo/client\" (CJS)": 46868,
+  "import { ApolloClient, InMemoryCache, HttpLink } from \"@apollo/client\" (production) (CJS)": 41523,
+  "import { ApolloClient, InMemoryCache, HttpLink } from \"@apollo/client\"": 35530,
+  "import { ApolloClient, InMemoryCache, HttpLink } from \"@apollo/client\" (production)": 29301
 }