Bump workflow actions to fix deprecation warnings

Author: mikemanger

.github/workflows/main.yml

@@ -21,9 +21,9 @@ jobs:
         - '3.11'
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
 
-    - uses: actions/setup-python@v4
+    - uses: actions/setup-python@v5
       with:
         python-version: ${{ matrix.python-version }}
         cache: pip