chore(deps): update actions/checkout action to v6 (#41)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/deploy_docs.yaml

@@ -10,7 +10,7 @@ jobs:
     name: Deploy docs
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v6
 
       - name: Install python 3.11
         uses: actions/setup-python@v4

.github/workflows/release_pypi.yaml

@@ -16,7 +16,7 @@ jobs:
       id-token: write
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v6
       - name: Set up Python
         uses: actions/setup-python@v4
         with:

.github/workflows/test.yaml

@@ -22,7 +22,7 @@ jobs:
           - "3.12"
           - "3.13"
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v6
 
       - name: Install python ${{ matrix.python-version }}
         uses: actions/setup-python@v4
@@ -58,7 +58,7 @@ jobs:
     name: Formatting check
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           # Full git history is needed to get a proper list of changed test_files within `super-linter`
           fetch-depth: 0
@@ -89,7 +89,7 @@ jobs:
     name: Test docs
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v6
 
       - name: Install python 3.11
         uses: actions/setup-python@v4