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/black.yml

@@ -10,5 +10,5 @@ jobs:
   lint:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: psf/black@stable

.github/workflows/build-flake.yml

@@ -18,7 +18,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
     - name: Set up Python 3.10
       uses: actions/setup-python@v5
       with:

.github/workflows/check_install_dev.yml

@@ -28,7 +28,7 @@ jobs:
                 #       runs-on: macos-latest
                 #       allow_failure: true
         steps:
-            - uses: actions/checkout@v4
+            - uses: actions/checkout@v6
 
             - name: Setup Python ${{ matrix.python-version }}
               uses: actions/setup-python@v5

.github/workflows/check_install_main.yml

@@ -28,7 +28,7 @@ jobs:
                 #       runs-on: macos-latest
                 #       allow_failure: true
         steps:
-            - uses: actions/checkout@v4
+            - uses: actions/checkout@v6
 
             - name: Setup Python ${{ matrix.python-version }}
               uses: actions/setup-python@v5

.github/workflows/check_install_quick.yml

@@ -28,7 +28,7 @@ jobs:
                 #       runs-on: macos-latest
                 #       allow_failure: true
         steps:
-            - uses: actions/checkout@v4
+            - uses: actions/checkout@v6
 
             - name: Setup Python ${{ matrix.python-version }}
               uses: actions/setup-python@v5

.github/workflows/linter.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           # Full git history is needed to get a proper list of changed files within `super-linter`
           fetch-depth: 0