CI: add job to build debian package

.github/workflows/test-build.yml

@@ -0,0 +1,40 @@
+name: test-build
+on:
+  workflow_dispatch:
+  pull_request:
+  push:
+  schedule:
+    - cron: '30 3 * * 2'
+
+concurrency:
+  group: "${{ github.ref }}"
+  cancel-in-progress: true
+jobs:
+  build-debian:
+    strategy:
+      # Keep other matrix jobs running, even if one fails.
+      fail-fast: false
+      matrix:
+        host_release:
+        - unstable
+        - trixie
+        - bookworm
+
+    # We want a working shell, qemu, python and docker. Specific version should not matter (much).
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - run: ./test/gha-build-deb.sh
+      name: "Build .deb for ${{matrix.host_release}}"
+      env:
+        HOST_RELEASE: ${{matrix.host_release}}
+
+    - name: Archive built .deb
+      uses: actions/upload-artifact@v4
+      with:
+        name: deb-${{matrix.host_release}}
+        if-no-files-found: error
+        path: |
+          *.deb