chore(deps): update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/ci-cd.yml

@@ -16,7 +16,7 @@ jobs:
       matrix:
         python-version: ["3.10", "3.11", "3.12", "3.13"]
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Install uv
         uses: astral-sh/setup-uv@v7
         with:
@@ -47,10 +47,10 @@ jobs:
       CODECOV_MD_FILE: "coverage.md"
       CODECOV_REPORT_TITLE: "Code coverage report"
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           ref: main
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Install uv
         uses: astral-sh/setup-uv@v7
         with:
@@ -124,7 +124,7 @@ jobs:
     runs-on: ubuntu-latest
     needs: ci
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Install uv
         uses: astral-sh/setup-uv@v7
         with:
@@ -202,7 +202,7 @@ jobs:
     permissions:
       contents: write
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Download package build artifacts
         uses: actions/download-artifact@v6
         with:
@@ -244,7 +244,7 @@ jobs:
       id-token: write
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Install uv
         uses: astral-sh/setup-uv@v7
         with: