Udpate GitHub Actions pins.

Author: fschulze

.github/workflows/main.yml

@@ -29,8 +29,8 @@ jobs:
     runs-on: "${{ matrix.os }}"
 
     steps:
-      - uses: "actions/checkout@v3"
-      - uses: "actions/setup-python@v4"
+      - uses: "actions/checkout@v4"
+      - uses: "actions/setup-python@v5"
         with:
           python-version: "${{ matrix.python-version }}"
       - name: "Install dependencies"
@@ -69,8 +69,8 @@ jobs:
     runs-on: "${{ matrix.os }}"
 
     steps:
-      - uses: "actions/checkout@v3"
-      - uses: "actions/setup-python@v4"
+      - uses: "actions/checkout@v4"
+      - uses: "actions/setup-python@v5"
         with:
           python-version: "${{ matrix.python-version }}"
       - name: "Install dependencies"
@@ -93,8 +93,8 @@ jobs:
     runs-on: "ubuntu-latest"
 
     steps:
-      - uses: "actions/checkout@v3"
-      - uses: "actions/setup-python@v4"
+      - uses: "actions/checkout@v4"
+      - uses: "actions/setup-python@v5"
         with:
           python-version: "3.x"
       - name: "Install dependencies"