chore(deps): update actions/github-script action to v8 (#354)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
|
[actions/github-script](https://redirect.github.com/actions/github-script)
| action | major | `v7` -> `v8` |

---

### Release Notes

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

###
[`v8`](https://redirect.github.com/actions/github-script/releases/tag/v8):
.0.0

[Compare
Source](https://redirect.github.com/actions/github-script/compare/v7...v8)

##### What's Changed

- Update Node.js version support to 24.x by
[@&#8203;salmanmkc](https://redirect.github.com/salmanmkc) in
[#&#8203;637](https://redirect.github.com/actions/github-script/pull/637)
- README for updating actions/github-script from v7 to v8 by
[@&#8203;sneha-krip](https://redirect.github.com/sneha-krip) in
[#&#8203;653](https://redirect.github.com/actions/github-script/pull/653)

##### ⚠️ Minimum Compatible Runner Version

**v2.327.1**\
[Release
Notes](https://redirect.github.com/actions/runner/releases/tag/v2.327.1)

Make sure your runner is updated to this version or newer to use this
release.

##### New Contributors

- [@&#8203;salmanmkc](https://redirect.github.com/salmanmkc) made their
first contribution in
[#&#8203;637](https://redirect.github.com/actions/github-script/pull/637)
- [@&#8203;sneha-krip](https://redirect.github.com/sneha-krip) made
their first contribution in
[#&#8203;653](https://redirect.github.com/actions/github-script/pull/653)

**Full Changelog**:
<actions/github-script@v7.1.0...v8.0.0>

</details>

---

### Configuration

📅 **Schedule**: Branch creation - At any time (no schedule defined),
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/ObolNetwork/charon-distributed-validator-node).

<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiI0MS45MS4xIiwidXBkYXRlZEluVmVyIjoiNDEuMTMxLjkiLCJ0YXJnZXRCcmFuY2giOiJtYWluIiwibGFiZWxzIjpbXX0=-->

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

Author: renovate[bot]

.github/workflows/label-issues.yml

@@ -10,7 +10,7 @@ jobs:
     permissions:
       issues: write
     steps:
-      - uses: actions/github-script@v7
+      - uses: actions/github-script@v8
         with:
           script: |
             github.rest.issues.addLabels({