CI: Linux griffin unity build

make -f Makefile.griffin platform=unix, on every push and pull request.

.github/workflows/Linux-griffin.yml

@@ -0,0 +1,88 @@
+name: CI Linux Griffin [Unity build]
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+
+permissions:
+  contents: read
+
+env:
+  ACTIONS_ALLOW_USE_UNSECURE_NODE_VERSION: true
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: ${{ github.ref != 'refs/heads/master' }}
+
+jobs:
+  linux-griffin: # griffin/griffin.c as Makefile.griffin builds it for Linux
+    runs-on: ubuntu-latest
+    env:
+      APT_PKGS: build-essential libgl-dev libudev-dev libpulse-dev libx11-dev libx11-xcb-dev libxcb1-dev libxxf86vm-dev ccache
+    timeout-minutes: 30
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v5
+
+      - name: Apt cache key
+        id: apt
+        run: sh .github/workflows/scripts/apt-cache-key.sh "$APT_PKGS"
+
+      - name: Restore apt cache
+        uses: actions/cache/restore@v4
+        with:
+          path: ~/.apt-cache
+          key: ${{ steps.apt.outputs.key }}
+          restore-keys: ${{ steps.apt.outputs.prefix }}
+
+      - name: Install dependencies
+        timeout-minutes: 20
+        run: sh .github/workflows/scripts/apt-install.sh $APT_PKGS
+
+      - name: Save apt cache
+        if: env.APT_CACHE_SAVE == '1'
+        uses: actions/cache/save@v4
+        with:
+          path: ~/.apt-cache
+          key: ${{ steps.apt.outputs.key }}
+
+      - name: Link with lld
+        run: sh .github/workflows/scripts/use-lld.sh
+
+      - name: Restore ccache
+        uses: actions/cache/restore@v4
+        with:
+          path: ~/.ccache
+          key: ccache-${{ github.workflow }}-${{ github.job }}-${{ github.sha }}
+          restore-keys: |
+            ccache-${{ github.workflow }}-${{ github.job }}-
+
+      - name: Enable ccache
+        run: |
+          set -eu
+          export CCACHE_DIR="$HOME/.ccache"
+          echo "CCACHE_DIR=$CCACHE_DIR" >> "$GITHUB_ENV"
+          echo "/usr/lib/ccache" >> "$GITHUB_PATH"
+          ccache -M 250M
+          ccache -z
+
+      - name: Build
+        run: make -f Makefile.griffin platform=unix -j"$(nproc)"
+
+      - name: ccache statistics
+        if: ${{ !cancelled() }}
+        continue-on-error: true
+        run: ccache -sv
+
+      - name: Save ccache
+        # Only master's pushes keep a cache: pull requests restore
+        # master's, so one push does not evict the next one's.
+        if: success() && github.event_name == 'push' && github.ref == 'refs/heads/master'
+        uses: actions/cache/save@v4
+        with:
+          path: ~/.ccache
+          key: ccache-${{ github.workflow }}-${{ github.job }}-${{ github.sha }}