Update actions/checkout digest to b4ffde6 (#156)

[![Mend
Renovate](https://app.renovatebot.com/images/banner.svg)](https://renovatebot.com)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [actions/checkout](https://togithub.com/actions/checkout) | action |
digest | `8ade135` -> `b4ffde6` |

---

### 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 has been generated by [Mend
Renovate](https://www.mend.io/free-developer-tools/renovate/). View
repository job log
[here](https://developer.mend.io/github/quiltdata/nf-quilt).

<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiIzNy4xOS4yIiwidXBkYXRlZEluVmVyIjoiMzcuODEuMyIsInRhcmdldEJyYW5jaCI6Im1haW4ifQ==-->

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

.github/workflows/mega-linter.yml

@@ -27,7 +27,7 @@ jobs:
     steps:
       # Git Checkout
       - name: Checkout Code
-        uses: actions/checkout@8ade135a41bc03ea155e62e844d188df1ea18608 # v4
+        uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4
         with:
           token: ${{ secrets.PAT || secrets.GITHUB_TOKEN }}
           fetch-depth: 0 # If you use VALIDATE_ALL_CODEBASE = true, you can remove this line to improve performances

.github/workflows/pkg-test.yml

@@ -27,7 +27,7 @@ jobs:
     steps:
     # Git Checkout
     - name: Checkout Code
-      uses: actions/checkout@8ade135a41bc03ea155e62e844d188df1ea18608 # v4
+      uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4
       with:
         token: ${{ secrets.GITHUB_TOKEN }}
         fetch-depth: 0

.github/workflows/test.yml

@@ -27,7 +27,7 @@ jobs:
     steps:
     # Git Checkout
     - name: Checkout Code
-      uses: actions/checkout@8ade135a41bc03ea155e62e844d188df1ea18608 # v4
+      uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4
       with:
         token: ${{ secrets.GITHUB_TOKEN }}
         fetch-depth: 0