Bump actions/checkout from 5 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 5 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v5...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/automated-tests.yaml

@@ -22,7 +22,7 @@ jobs:
     timeout-minutes: 15
     steps:
       - name: "Checkout code"
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: "Use Node.js"
         uses: actions/setup-node@v6
         with:
@@ -49,7 +49,7 @@ jobs:
           sudo apt-get update
           sudo apt-get install -y libnss3 libasound2t64 labwc
       - name: "Checkout code"
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: "Use Node.js ${{ matrix.node-version }}"
         uses: actions/setup-node@v6
         with:

.github/workflows/dep-review.yaml

@@ -13,6 +13,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: "Checkout code"
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: "Dependency Review"
         uses: actions/dependency-review-action@v4

.github/workflows/electron-rebuild.yaml

@@ -11,7 +11,7 @@ jobs:
         node-version: [22.20.0, 22.x, 24.x]
     steps:
       - name: Checkout code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: "Use Node.js ${{ matrix.node-version }}"
         uses: actions/setup-node@v6
         with:

.github/workflows/spellcheck.yaml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           ref: develop
       - name: Set up Node.js