Add github action to build Mac release

.github/workflows/mac.yml

@@ -0,0 +1,40 @@
+name: SDRangel Mac release build
+
+on:
+  push:
+    branches:
+      - mac_ci
+    tags:
+      - 'v*'
+
+jobs:
+  build_mac_arm:
+    runs-on: macos-14
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          submodules: true
+          fetch-depth: 0
+      - name: Configure SDRangel
+        run: |
+          mkdir build && cd build
+          cmake .. -DCMAKE_VERBOSE_MAKEFILE=ON -DENABLE_QT6=ON -DCMAKE_BUILD_TYPE=Release -DARCH_OPT=nehalem -DDEBUG_OUTPUT=ON -DENABLE_CHANNELRX_DEMODDATV=OFF -DENABLE_CHANNELTX_MODDATV=OFF -DENABLE_MIRISDR=OFF -DBUILD_SERVER=OFF -DENABLE_EXTERNAL_LIBRARIES=ON -DBUNDLE=ON -DPKG_CONFIG_USE_CMAKE_PREFIX_PATH=TRUE
+      - name: Build SDRangel on Mac
+        run: |
+          cd build
+          make -j3 all
+      - name: Build dmg
+        run: |
+          cd build
+          make package
+      - name: Get version
+        id: get_version
+        run: echo "version=$(echo ${{github.ref_name}} | cut -c2-)" >> $env:GITHUB_OUTPUT
+      - name: Get filename
+        id: get_filename
+        run: echo "filename=$(grep CPACK_PACKAGE_FILE_NAME build/CMakeCache.txt | cut -d "=" -f2)" >> $GITHUB_OUTPUT
+      - name: Upload artifact
+        uses: actions/upload-artifact@v3
+        with:
+          name: sdrangel-${{ steps.get_version.outputs.version }}-macarm.dmg
+          path: ${{ github.workspace }}/build/${{ steps.get_filename.outputs.filename }}.dmg