Upgrade deprecated GitHub Actions steps

.github/workflows/main.yml

@@ -15,7 +15,7 @@ jobs:
       fail-fast: false
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
 
     - name: Install dependencies
       run: $PIP install virtualenv tox
@@ -50,13 +50,13 @@ jobs:
       fail-fast: false
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
 
     - name: Work around pip SSL cert verify error
       run: sudo $PIP config set global.trusted-host 'pypi.python.org pypi.org files.pythonhosted.org'
 
     - name: Set up Python 3.5
-      uses: actions/setup-python@v4
+      uses: actions/setup-python@v5
       with:
         python-version: 3.5
 
@@ -81,10 +81,10 @@ jobs:
         python-version: [3.6, 3.7, 3.8, 3.9, "3.10", 3.11, 3.12]
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
 
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v4
+      uses: actions/setup-python@v5
       with:
         python-version: ${{ matrix.python-version }}
 
@@ -108,7 +108,7 @@ jobs:
       fail-fast: false
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
 
     - name: Install dependencies
       run: $PIP install virtualenv tox
@@ -124,10 +124,10 @@ jobs:
         python-version: [3.8]
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
 
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v4
+      uses: actions/setup-python@v5
       with:
         python-version: ${{ matrix.python-version }}
 
@@ -141,10 +141,10 @@ jobs:
     runs-on: ubuntu-20.04
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
 
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v4
+      uses: actions/setup-python@v5
       with:
         python-version: "3.8"