CI: add a Qt6 build

.github/workflows/nightly-neon-qt6.yml

@@ -0,0 +1,41 @@
+name: nightly-neon
+
+on:
+  schedule:
+    - cron: "52 23 * * *"
+  workflow_dispatch:
+
+env:
+  BUILDDIR: /build
+  SRCDIR: ${{ github.workspace }}
+  CMAKE_ARGS: |
+    -DKDE_INSTALL_USE_QT_SYS_PATHS=ON
+    -DCMAKE_BUILD_TYPE=Debug
+    -DWITH_QT6=ON
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    container:
+      image: docker://kdeneon/plasma:user
+      options: --tmpfs /build:rw --user 0:0
+    steps:
+      - name: "prepare env"
+        uses: calamares/actions/prepare-neon@v4
+      - name: "prepare source"
+        uses: calamares/actions/generic-checkout@v4
+      - name: "build"
+        id: build
+        uses: calamares/actions/generic-build@v4
+      - name: "Calamares: archive"
+        working-directory: ${{ env.BUILDDIR }}
+        run: |
+          make install DESTDIR=${{ env.BUILDDIR }}/stage
+          tar czf calamares.tar.gz stage
+      - name: "Calamares: upload"
+        uses: actions/upload-artifact@v2
+        with:
+          name: calamares-tarball
+          path: ${{ env.BUILDDIR }}/calamares.tar.gz
+          if-no-files-found: error
+          retention-days: 7