Bump actions/checkout from 4 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 4 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v4...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/ci.yml

@@ -12,7 +12,7 @@ jobs:
     name: Quality (ruff + ty)
     runs-on: ubuntu-24.04
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Install i18n tooling
         run: |
@@ -70,7 +70,7 @@ jobs:
           - ubuntu: "24.04"
             python: "3.12"
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Cache pip downloads
         uses: actions/cache@v4
@@ -156,7 +156,7 @@ jobs:
     container:
       image: ${{ matrix.image }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Cache pip downloads
         uses: actions/cache@v4
@@ -194,7 +194,7 @@ jobs:
     runs-on: ubuntu-22.04
     needs: [test-ubuntu, test-debian]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Install build dependencies
         run: |
@@ -259,7 +259,7 @@ jobs:
     runs-on: ubuntu-22.04
     needs: [test-ubuntu, test-debian]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Install RPM tooling
         run: |
@@ -285,7 +285,7 @@ jobs:
     runs-on: ubuntu-22.04
     needs: [test-ubuntu, test-debian]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Install Flatpak tooling
         run: |
@@ -315,7 +315,7 @@ jobs:
     runs-on: ubuntu-22.04
     needs: [test-ubuntu, test-debian]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Install Snapcraft
         run: |
@@ -346,7 +346,7 @@ jobs:
     runs-on: ubuntu-22.04
     needs: [test-ubuntu, test-debian]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Install AppImage tooling
         run: |
@@ -376,7 +376,7 @@ jobs:
     container:
       image: archlinux:latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Install Arch build tooling
         run: |
@@ -405,7 +405,7 @@ jobs:
     runs-on: ubuntu-22.04
     needs: [test-ubuntu, test-debian]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Install Nix
         uses: cachix/install-nix-action@v30
@@ -441,7 +441,7 @@ jobs:
     permissions:
       contents: write
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Get version from pyproject.toml
         id: version

.github/workflows/security.yml

@@ -13,7 +13,7 @@ jobs:
     name: Dependency and SAST scan
     runs-on: ubuntu-22.04
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - uses: actions/setup-python@v5
         with: