upgrade GH actions (#397)

Author: benjaminp

.github/workflows/ci.yml

@@ -65,7 +65,7 @@ jobs:
     env:
       TOXENV: py
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - if: ${{ matrix.python-version == '2.7' }}
         run: |
           sudo apt-get install python-is-python2
@@ -74,7 +74,7 @@ jobs:
         name: Set up Python ${{ matrix.python-version }} on ${{ matrix.os }}
       - if: ${{ matrix.python-version != '2.7' }}
         name: Set up Python ${{ matrix.python-version }} on ${{ matrix.os }}
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: ${{ matrix.python-version }}
           allow-prereleases: true

.github/workflows/publish.yml

@@ -10,9 +10,9 @@ jobs:
   deploy:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
     - name: Set up Python
-      uses: actions/setup-python@v5
+      uses: actions/setup-python@v6
       with:
         python-version: '3.13'
     - name: Install dependencies