Add -Dofficial_release=true when a new tag is published (#214)

When a new tag is published, run the workflow to build the actifact with the arg "-Dofficial_release=true"

.github/workflows/ci.yml

@@ -3,6 +3,7 @@ name: Meson CI
 on:
   push:
     branches: [ master ]
+    tags: [ 'v*' ]
   pull_request:
     branches: [ master ]
   workflow_dispatch:
@@ -122,7 +123,7 @@ jobs:
           sudo apt-get install ninja-build build-essential libx11-dev libwxgtk3.0-gtk3-dev libfreetype6-dev pkg-config libfontconfig1-dev libass-dev libasound2-dev libffms2-dev intltool libboost-all-dev
 
       - name: Configure
-        run: meson build ${{ matrix.config.args }} -Dbuildtype=${{ matrix.config.buildtype }}
+        run: meson build ${{ matrix.config.args }} -Dbuildtype=${{ matrix.config.buildtype }} ${{ github.ref_type == 'tag' && '-Dofficial_release=true' || '' }}
 
       - name: Build
         run: meson compile -C build