Use tag version in build

Forward the version number from the tag to the build so it's shown in
the *about* dialog.

Author: ServiusHack

.github/workflows/release.yml

@@ -19,7 +19,7 @@ jobs:
         submodules: 'true'
 
     - name: Configure CMake
-      run: cmake -B ${{github.workspace}}/build -DCMAKE_BUILD_TYPE=${{env.BUILD_TYPE}}
+      run: cmake -B ${{github.workspace}}/build -DCMAKE_BUILD_TYPE=${{env.BUILD_TYPE}} -DVERSION=${{github.ref_name}}
 
     - name: Build
       run: cmake --build ${{github.workspace}}/build --config ${{env.BUILD_TYPE}}