Update actions/checkout action to v7 (#146)

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

Author: renovate[bot]

.github/workflows/build.yml

@@ -12,7 +12,7 @@ jobs:
         python-version: ['3.9', '3.10', '3.11', '3.12']
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v7
       with:
         submodules: recursive
     - name: Set up Python ${{ matrix.python-version }}

.github/workflows/format.yml

@@ -6,7 +6,7 @@ jobs:
   format:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v7
         with:
           ref: ${{ github.head_ref }}
       - name: Set up Python

.github/workflows/tests.yml

@@ -12,7 +12,7 @@ jobs:
         python-version: ['3.9', '3.10', '3.11', '3.12']
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v7
         with:
           submodules: recursive
       - name: Set up Python ${{ matrix.python-version }}