chore: Update GitHub actions

Author: georgedouzas

.github/workflows/ci-docs.yml

@@ -20,7 +20,7 @@ jobs:
 
     steps:
     - name: Checkout
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
 
     - name: Install Python versions
       uses: actions/setup-python@v4
@@ -59,7 +59,7 @@ jobs:
 
     steps:
     - name: Checkout
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
 
     - name: Install Python versions
       uses: actions/setup-python@v4
@@ -91,7 +91,7 @@ jobs:
 
     steps:
     - name: Checkout
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
 
     - name: Set up PDM
       uses: pdm-project/setup-pdm@v3

.github/workflows/ci.yml

@@ -19,7 +19,7 @@ jobs:
 
     steps:
     - name: Checkout
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
 
     - name: Install Python versions
       uses: actions/setup-python@v4
@@ -61,7 +61,7 @@ jobs:
 
     steps:
     - name: Checkout
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
 
     - name: Install Python versions
       uses: actions/setup-python@v4

.github/workflows/doc.yml

@@ -26,7 +26,7 @@ jobs:
 
     steps:
     - name: Checkout
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
 
     - name: Setup Pages
       uses: actions/configure-pages@v3