Update actions/checkout action to v4

Author: renovate[bot]

.github/workflows/build.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up Python env
         uses: actions/setup-python@v4
         with:

.github/workflows/docker-image.yaml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Docker meta
       id: meta
       uses: docker/metadata-action@v4

.github/workflows/test.yml

@@ -29,7 +29,7 @@ jobs:
         python-version: ['3.8', '3.9', '3.10']
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v4
         with:
@@ -74,7 +74,7 @@ jobs:
   Upload_to_test_pypi:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up Python
         uses: actions/setup-python@v4
         with: