chore(deps): update actions/checkout action to v5 (#203)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [actions/checkout](https://github.com/actions/checkout) | action | major | `v4.3.0` -> `v5.0.0` |

---

### Release Notes

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

### [`v5.0.0`](https://github.com/actions/checkout/releases/tag/v5.0.0)

[Compare Source](actions/checkout@v4.3.0...v5.0.0)

#### What's Changed

- Update actions checkout to use node 24 by [@&#8203;salmanmkc](https://github.com/salmanmkc) in [#&#8203;2226](actions/checkout#2226)
- Prepare v5.0.0 release by [@&#8203;salmanmkc](https://github.com/salmanmkc) in [#&#8203;2238](actions/checkout#2238)

#### ⚠️ Minimum Compatible Runner Version

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

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

**Full Changelog**: <actions/checkout@v4...v5.0.0>

</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 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 has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).
<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiI0MS42MS4xIiwidXBkYXRlZEluVmVyIjoiNDEuODEuNCIsInRhcmdldEJyYW5jaCI6Im1haW4iLCJsYWJlbHMiOlsidHlwZS9kZXBlbmRlbmNpZXMiXX0=-->

Reviewed-on: https://git.tainton.uk/luke/instant-msg-api/pulls/203
Co-authored-by: Renovate [BOT] <renovate-bot@git.tainton.uk>
Co-committed-by: Renovate [BOT] <renovate-bot@git.tainton.uk>

Author: Renovate [BOT]

.gitea/workflows/ci.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out repository code
-        uses: actions/checkout@v4.3.0
+        uses: actions/checkout@v5.0.0
         with:
           fetch-depth: 0
 

.gitea/workflows/release.yml

@@ -24,7 +24,7 @@ jobs:
       clean_changelog: ${{ steps.get_next_version.outputs.clean_changelog }}
     steps:
       - name: Check out repository
-        uses: actions/checkout@v4.3.0
+        uses: actions/checkout@v5.0.0
         with:
           fetch-depth: 0
 
@@ -79,7 +79,7 @@ jobs:
       release_name: ${{ steps.create_release_job.outputs.tag }}
     steps:
       - name: Check out repository
-        uses: actions/checkout@v4.3.0
+        uses: actions/checkout@v5.0.0
         with:
           fetch-depth: 0