chore(deps): update actions/checkout action to v6 (#179)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [actions/checkout](https://github.com/actions/checkout) | action | major | `v5.0.1` -> `v6.0.0` |

---

### Release Notes

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

### [`v6.0.0`](https://github.com/actions/checkout/releases/tag/v6.0.0)

[Compare Source](actions/checkout@v5.0.1...v6.0.0)

#### What's Changed

- Update README to include Node.js 24 support details and requirements by [@&#8203;salmanmkc](https://github.com/salmanmkc) in [#&#8203;2248](actions/checkout#2248)
- Persist creds to a separate file by [@&#8203;ericsciple](https://github.com/ericsciple) in [#&#8203;2286](actions/checkout#2286)
- v6-beta by [@&#8203;ericsciple](https://github.com/ericsciple) in [#&#8203;2298](actions/checkout#2298)
- update readme/changelog for v6 by [@&#8203;ericsciple](https://github.com/ericsciple) in [#&#8203;2311](actions/checkout#2311)

**Full Changelog**: <actions/checkout@v5.0.0...v6.0.0>

</details>

---

### Configuration

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🚦 **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:eyJjcmVhdGVkSW5WZXIiOiI0Mi4xOC4wIiwidXBkYXRlZEluVmVyIjoiNDIuMTguMCIsInRhcmdldEJyYW5jaCI6Im1haW4iLCJsYWJlbHMiOlsidHlwZS9kZXBlbmRlbmNpZXMiXX0=-->

Reviewed-on: https://git.tainton.uk/repos/epage/pulls/179
Co-authored-by: renovate[bot] <[email protected]>
Co-committed-by: renovate[bot] <[email protected]>

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@v5.0.1
+        uses: actions/checkout@v6.0.0
         with:
           fetch-depth: 0
 

.gitea/workflows/release.yml

@@ -45,7 +45,7 @@ jobs:
           REPO: ${{ gitea.repository }}
 
       - name: Check out repository
-        uses: actions/checkout@v5.0.1
+        uses: actions/checkout@v6.0.0
         with:
           fetch-depth: 0
           ref: ${{ needs.tag.outputs.tag_name }}

.gitea/workflows/snyk.yml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repo
-        uses: actions/checkout@v5.0.1
+        uses: actions/checkout@v6.0.0
 
       - name: Snyk
         uses: snyk/actions/python@master