Renovate: Update actions/github-script action to v9 (#696)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
|
[actions/github-script](https://redirect.github.com/actions/github-script)
| action | major | `v8` → `v9` |

---

### Release Notes

<details>
<summary>actions/github-script (actions/github-script)</summary>

###
[`v9`](https://redirect.github.com/actions/github-script/compare/v8...v9)

[Compare
Source](https://redirect.github.com/actions/github-script/compare/v8...v9)

</details>

---

### Configuration

📅 **Schedule**: (UTC)

- Branch creation
  - "before 8am on Friday"
- Automerge
  - At any time (no schedule defined)

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

♻ **Rebasing**: Whenever PR becomes conflicted, 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/cobaltcore-dev/cortex).

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

Author: renovate[bot]

.github/workflows/test.yaml

@@ -60,7 +60,7 @@ jobs:
       # Steps below are only executed if the workflow is triggered by a pull request
       - name: Delete old coverage comments (PR only)
         if: ${{ github.event_name == 'pull_request' }}
-        uses: actions/github-script@v8
+        uses: actions/github-script@v9
         with:
           script: |
             const { data: comments } = await github.rest.issues.listComments({
@@ -86,7 +86,7 @@ jobs:
           path: .
       - name: Post coverage comment (PR only)
         if: ${{ github.event_name == 'pull_request' }}
-        uses: actions/github-script@v8
+        uses: actions/github-script@v9
         # For external contributors, posting comments fail due to permission issues.
         continue-on-error: true
         with: