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] <support@github.com>

Author: dependabot[bot]

.github/workflows/app-build.yml

@@ -26,7 +26,7 @@ jobs:
     name: Build app (${{ matrix.app-build-types }})
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Capitalise build type
         id: capitalise-build-type
         # See https://linuxhint.com/bash_lowercase_uppercase_strings/

.github/workflows/checks.yml

@@ -22,7 +22,7 @@ jobs:
     name: Unit tests
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Run unit tests
         uses: ./.github/actions/build-gradle
         with:
@@ -45,7 +45,7 @@ jobs:
       # For generating checks
       checks: write
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Run dependencyUpdates task
         uses: ./.github/actions/build-gradle
         with:
@@ -92,7 +92,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Run lint task
         uses: ./.github/actions/build-gradle
         with:
@@ -117,7 +117,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Run buildHealth task
         uses: ./.github/actions/build-gradle
         with:

.github/workflows/dependency-submission.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout sources
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Setup Java
         uses: actions/setup-java@v5
         with:

.github/workflows/manual-checks.yml

@@ -21,7 +21,7 @@ jobs:
           echo 'KERNEL=="kvm", GROUP="kvm", MODE="0666", OPTIONS+="static_node=kvm"' | sudo tee /etc/udev/rules.d/99-kvm4all.rules
           sudo udevadm control --reload-rules
           sudo udevadm trigger --name-match=kvm
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Setup Java 17
         uses: actions/setup-java@v5
         with:

.github/workflows/nightly.yml

@@ -17,7 +17,7 @@ jobs:
     if: ${{ startsWith(github.repository, 'EdricChan03') }}
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Build nightly app
         uses: ./.github/actions/build-gradle
         with:

.github/workflows/pull-request.yml

@@ -9,7 +9,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Build app
         uses: ./.github/actions/build-gradle
         with:
@@ -28,7 +28,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Run unit tests
         uses: ./.github/actions/build-gradle
         with:
@@ -48,7 +48,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Run lint task
         uses: ./.github/actions/build-gradle
         with: