Bump actions/checkout from 4 to 6 (#11)

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

Author: dependabot[bot]

.github/workflows/test.yml

@@ -11,7 +11,7 @@ jobs:
   test-basic:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Create test project
         run: |
@@ -46,7 +46,7 @@ jobs:
   test-default-sync:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Create test project
         run: |
@@ -81,7 +81,7 @@ jobs:
   test-requirements:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Create test project
         run: |
@@ -120,7 +120,7 @@ jobs:
   test-custom-requirements:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Create test project
         run: |
@@ -158,7 +158,7 @@ jobs:
   test-requirements-failure:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Install uv
         run: |
           curl -LsSf https://astral.sh/uv/install.sh | sh
@@ -183,7 +183,7 @@ jobs:
   test-multiple-requirements:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Create test project
         run: |
           mkdir -p test-project
@@ -233,7 +233,7 @@ jobs:
   test-failure:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Install uv
         run: |
           curl -LsSf https://astral.sh/uv/install.sh | sh
@@ -258,7 +258,7 @@ jobs:
   test-python-version-tilde:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Install uv
         run: |
           curl -LsSf https://astral.sh/uv/install.sh | sh