Update GH actions to versions running Node.js 20

Fixes warnings:
"Node.js 16 actions are deprecated. Please update the following
actions to use Node.js 20"

See also:
https://github.blog/changelog/2023-09-22-github-actions-transitioning-from-node-16-to-node-20/

.github/workflows/build.yml

@@ -36,9 +36,9 @@ jobs:
           sudo apt-get -y update
           sudo apt-get install libcups2-dev wamerican
 
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python-version }}
 
@@ -48,7 +48,7 @@ jobs:
           echo "dir=$(pip cache dir)" >>$GITHUB_OUTPUT
 
       - name: Cache
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ${{ steps.pip-cache.outputs.dir }}
           key: