Add workflow to create tarball for Linux

.github/workflows/package-linux-tarball.yml

@@ -0,0 +1,80 @@
+name: package-linux-tarball
+
+on:
+  release:
+    types: [created]
+
+jobs:
+  linux-clang-build:
+    runs-on: ubuntu-20.04
+
+    env:
+      SCCACHE_GHA_ENABLED: "true"
+      SCCACHE_CACHE_SIZE: "2G"
+
+    steps:
+    - uses: actions/checkout@v1
+      with:
+        submodules: true
+
+    - name: install dependencies
+      run: | 
+        sudo apt install cmake \
+        '^libxcb.*-dev' \
+        libgl1-mesa-dev \
+        ninja-build \
+        python3 \
+        libeigen3-dev \
+        zlib1g-dev \
+        libfftw3-dev \
+        libtiff5-dev \
+        libpng-dev
+
+    - name: Install Clang 17
+      run: |
+        wget https://apt.llvm.org/llvm.sh
+        chmod +x llvm.sh
+        sudo ./llvm.sh 17
+
+    - name: Install Qt
+      uses: jurplel/install-qt-action@v3
+      with:
+        version: '6.5.3'
+        host: 'linux'
+        arch: 'gcc_64'
+        cache-key-prefix: 'install-qt-action'
+        set-env: 'true'
+
+    - name: configure
+      run: >
+        cmake
+        -B build
+        -G Ninja
+        -D CMAKE_CXX_COMPILER=clang++-17
+        -D CMAKE_BUILD_TYPE=Release
+        -D MRTRIX_USE_QT6=ON
+
+    - name: build
+      run: cmake --build build
+
+    - name: install
+      run: cmake --install build --prefix ./mrtrix3_install
+
+    - name: Run linuxdeploy
+      run: |
+        wget "https://github.com/linuxdeploy/linuxdeploy/releases/download/continuous/linuxdeploy-x86_64.AppImage"
+        wget "https://github.com/linuxdeploy/linuxdeploy-plugin-qt/releases/download/continuous/linuxdeploy-plugin-qt-x86_64.AppImage"
+        chmod +x ./linuxdeploy-x86_64.AppImage
+        chmod +x ./linuxdeploy-plugin-qt-x86_64.AppImage
+        mkdir appdir && mkdir appdir/usr
+        cp -r mrtrix3_install/* appdir/usr
+        ./linuxdeploy-x86_64.AppImage --appdir appdir --plugin qt --verbosity=0
+    
+    - name: Create tarball
+      run: tar -czf mrtrix3-$(git describe --tags --abbrev=0)-linux.tar.gz appdir/usr
+
+    - name: Upload package to GitHub Release
+      uses: AButler/[email protected]
+      with:
+        files: '*.tar.gz'
+        repo-token: ${{ secrets.GITHUB_TOKEN }}