chore(deps): update actions/cache action to v5 (#1736)

This PR contains the following updates:

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

---

> [!WARNING]
> Some dependencies could not be looked up. Check the Dependency
Dashboard for more information.

---

### 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 - At any time (no schedule defined),
Automerge - At any time (no schedule defined).

🚦 **Automerge**: Enabled.

♻ **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

---

This PR was generated by [Mend Renovate](https://mend.io/renovate/).
View the [repository job
log](https://developer.mend.io/github/prometheus/client_java).

<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiI0Mi40Mi4yIiwidXBkYXRlZEluVmVyIjoiNDIuNDIuMiIsInRhcmdldEJyYW5jaCI6Im1haW4iLCJsYWJlbHMiOlsiZGVwZW5kZW5jaWVzIl19-->

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/build.yml

@@ -17,7 +17,7 @@ jobs:
           version: v2025.12.0
           sha256: 5b7b9992950b65569b4f6f1c78b05abceea2506f15b750a4b9781f33c6cc1ae4
       - name: Cache local Maven repository
-        uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4
+        uses: actions/cache@a7833574556fa59680c1b7cb190c1735db73ebf0 # v5
         with:
           path: ~/.m2/repository
           key: ${{ runner.os }}-maven-${{ hashFiles('**/pom.xml') }}

.github/workflows/test-release-build.yml

@@ -21,7 +21,7 @@ jobs:
           version: v2025.12.0
           sha256: 5b7b9992950b65569b4f6f1c78b05abceea2506f15b750a4b9781f33c6cc1ae4
       - name: Cache local Maven repository
-        uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4
+        uses: actions/cache@a7833574556fa59680c1b7cb190c1735db73ebf0 # v5
         with:
           path: ~/.m2/repository
           key: ${{ runner.os }}-maven-${{ hashFiles('**/pom.xml') }}