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/black.yml

@@ -23,7 +23,7 @@ jobs:
         with:
           access_token: ${{ secrets.GITHUB_TOKEN }}
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           submodules: true
       - name: Install the latest version of uv

.github/workflows/docker_deployment.yml

@@ -20,7 +20,7 @@ jobs:
         with:
           access_token: ${{ secrets.GITHUB_TOKEN }}
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           submodules: true
           fetch-depth: 0

.github/workflows/docs.yml

@@ -25,7 +25,7 @@ jobs:
           access_token: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           submodules: true
           fetch-depth: 0
@@ -97,7 +97,7 @@ jobs:
         shell: bash
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Download artifact
         uses: actions/download-artifact@v6.0.0
         with:

.github/workflows/macos_CI.yml

@@ -26,7 +26,7 @@ jobs:
           access_token: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           submodules: true
       - name: Set up Python ${{ matrix.python }}

.github/workflows/ubuntu.yml

@@ -26,7 +26,7 @@ jobs:
           access_token: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           submodules: true
 

.github/workflows/wheels.yml

@@ -19,7 +19,7 @@ jobs:
           access_token: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
             submodules: true
             fetch-depth: 0
@@ -55,7 +55,7 @@ jobs:
           access_token: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
             submodules: true
             fetch-depth: 0
@@ -87,7 +87,7 @@ jobs:
           access_token: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
             submodules: true
             fetch-depth: 0
@@ -115,7 +115,7 @@ jobs:
         with:
           access_token: ${{ secrets.GITHUB_TOKEN }}
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Download sdist
         uses: actions/download-artifact@v6.0.0
         with: