Bump actions/checkout from 5 to 6 (#25807)

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](https://github.com/actions/checkout/compare/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] <[e-mail]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/api.yml

···
     if: github.repository == 'qmk/qmk_firmware'
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         fetch-depth: 1
         persist-credentials: false

.github/workflows/auto_tag.yml

···
     if: github.repository == 'qmk/qmk_firmware'
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         fetch-depth: 0
 

.github/workflows/ci_build_major_branch.yml

···
           git config --global --add safe.directory '*'
 
       - name: Checkout QMK Firmware
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Determine concurrency
         id: generate_slice_length
···
           git config --global --add safe.directory '*'
 
       - name: Checkout QMK Firmware
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
 

.github/workflows/ci_build_major_branch_keymap.yml

···
           git config --global --add safe.directory '*'
 
       - name: Checkout QMK Firmware
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Generate build targets
         id: generate_targets
···
           git config --global --add safe.directory '*'
 
       - name: Checkout QMK Firmware
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Get target definitions
         uses: actions/download-artifact@v6
···
 
     steps:
       - name: Checkout QMK Firmware
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Download firmwares
         uses: actions/download-artifact@v6

.github/workflows/cli.yml

···
     - name: Disable safe.directory check
       run : git config --global --add safe.directory '*'
 
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         submodules: recursive
 

.github/workflows/develop_update.yml

···
     if: github.repository == 'qmk/qmk_firmware'
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         token: ${{ secrets.QMK_BOT_TOKEN }}
         fetch-depth: 0

.github/workflows/docs.yml

···
     container: ghcr.io/qmk/qmk_cli
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         fetch-depth: 1
 

.github/workflows/feature_branch_update.yml

···
         - riot
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         token: ${{ secrets.QMK_BOT_TOKEN }}
         fetch-depth: 0

.github/workflows/format.yml

···
     - name: Disable safe.directory check
       run : git config --global --add safe.directory '*'
 
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         fetch-depth: 0
 

.github/workflows/format_push.yml

···
     - name: Disable safe.directory check
       run : git config --global --add safe.directory '*'
 
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         fetch-depth: 0
 

.github/workflows/lint.yml

···
     - name: Disable safe.directory check
       run : git config --global --add safe.directory '*'
 
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         fetch-depth: 0
 

.github/workflows/regen.yml

···
     - name: Disable safe.directory check
       run : git config --global --add safe.directory '*'
 
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
 
     - name: Run qmk generators
       run: |

.github/workflows/regen_push.yml

···
     - name: Disable safe.directory check
       run : git config --global --add safe.directory '*'
 
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
 
     - name: Run qmk generators
       run: |

.github/workflows/unit_test.yml

···
     container: ghcr.io/qmk/qmk_cli
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         submodules: recursive
     - name: Install dependencies