Bump actions/checkout from 3 to 4

.github/workflows/codeql.yml

@@ -41,7 +41,7 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
 
     # Initializes the CodeQL tools for scanning.
     - name: Initialize CodeQL

.github/workflows/main.yml

@@ -8,7 +8,7 @@ jobs:
     name: Check Formatting
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - uses: actions/setup-python@v4
         with:
@@ -24,7 +24,7 @@ jobs:
     name: Run linting
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - uses: actions/setup-python@v4
         with:
@@ -40,7 +40,7 @@ jobs:
     name: Run type checking
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - uses: actions/setup-python@v4
         with:
@@ -64,7 +64,7 @@ jobs:
             toxenv: "py39"
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - uses: actions/setup-python@v4
         with:
@@ -86,7 +86,7 @@ jobs:
         # os: [ubuntu-20.04, windows-2019, macOS-10.15]
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - uses: actions/setup-python@v4
 
@@ -104,7 +104,7 @@ jobs:
     name: Build source distribution
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - uses: actions/setup-python@v4
         with: