Bump actions/checkout from 5 to 6 (#3646)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/check.yaml

@@ -33,7 +33,7 @@ jobs:
           - windows-2025
           - macos-15
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
       - name: Install the latest version of uv
@@ -75,7 +75,7 @@ jobs:
         exclude:
           - { os: windows-latest, tox_env: docs }
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
       - name: Install the latest version of uv

.github/workflows/release.yaml

@@ -11,7 +11,7 @@ jobs:
   build:
     runs-on: ubuntu-24.04
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
       - name: Install the latest version of uv

.github/workflows/weekly.yaml

@@ -31,7 +31,7 @@ jobs:
           - windows-2025
           - macos-15
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
       - name: Install the latest version of uv