CI: Update to latest actions version and base image

.github/workflows/ci-cross.yml

@@ -16,12 +16,12 @@ jobs:
     strategy:
       matrix:
         buildtype: [release, debug]
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Cache
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         id: cache
         with:
           path: ~/toolchain

.github/workflows/ci-native.yml

@@ -13,12 +13,16 @@ on:
 
 jobs:
   build:
+    # TODO: It would be nice to move away from Ubuntu 22.04, but that would
+    #       need either building WPE WebKit, finding a PPA for it, or using
+    #       a self-hosted runner with preconfigured base system including
+    #       the needed dependencies.
     runs-on: ubuntu-22.04
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Cache
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: |
             ~/.cache/pip
@@ -103,15 +107,15 @@ jobs:
   publish:
     if: ${{ github.ref == 'refs/heads/master' }}
     needs: build
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
     steps:
       - name: Fetch Documentation
-        uses: actions/download-artifact@v3
+        uses: actions/download-artifact@v4
         with:
           name: docs
           path: html
       - name: Deploy Documentation
-        uses: peaceiris/actions-gh-pages@v3
+        uses: peaceiris/actions-gh-pages@v4
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
           publish_dir: html

.github/workflows/codestyle.yml

@@ -8,22 +8,18 @@ on:
 
 jobs:
   check:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
     steps:
       - name: Checkout Head
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Fetch Git History
         run: |
           git fetch --no-tags --prune --depth=1 \
             origin +refs/heads/master:refs/remotes/origin/master
       - name: Install Tools
         run: |
-          curl -sL https://apt.llvm.org/llvm-snapshot.gpg.key | \
-            sudo apt-key add -
-          sudo add-apt-repository \
-            'deb http://apt.llvm.org/focal/ llvm-toolchain-focal-13 main'
           sudo apt update
-          sudo apt install -y clang-format-13 diffutils
+          sudo apt install -y clang-format-18 diffutils
       - name: Check
         run: |
           data/check-style -ocode-style.diff origin/master