Update GitHub actions

Author: encukou

.github/workflows/main.yml

@@ -8,18 +8,18 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
     - name: Set up Python
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v5
       with:
         python-version: 3.11
     - name: Poetry cache
-      uses: actions/cache@v2
+      uses: actions/cache@v4
       with:
         path: ~/.cache/pypoetry
         key: poetry-cache-${{ runner.os }}-${{ hashFiles('poetry.lock') }}-${{ hashFiles('.github/workflows/*.yml') }}
     - name: Pip cache
-      uses: actions/cache@v2
+      uses: actions/cache@v4
       with:
         path: ~/.cache/pip
         key: pip-cache-${{ runner.os }}-${{ hashFiles('.github/workflows/*.yml') }}