remove retrodrawing from build

.github/workflows/mainbuild.yml

@@ -43,10 +43,6 @@ jobs:
       run: |
         cd demo/AlienBuster
         mvn --batch-mode clean compile install package
-    - name: Build Retrodrawing cart
-      run: |
-        cd demo/Retrodrawing
-        mvn --batch-mode clean compile install package
     - name: Build Snake cart
       run: |
         cd demo/Snake
@@ -71,12 +67,6 @@ jobs:
       with:
         name: 'snake.omicron'
         path: demo/Snake/snake.omicron
-    - name: Deploy Retrodrawing Demo
-      uses: actions/upload-artifact@v4
-      with:
-        name: 'retrodrawing.omicron'
-        path: demo/Retrodrawing/retrodrawing.omicron
-
     - name: Setup Android SDK
       uses: android-actions/setup-android@v3
       with:
@@ -102,15 +92,6 @@ jobs:
       with:
         name: 'feature-demo.apk'
         path: android-mvn/target/feature-demo.apk
-    - name: Build retrodrawing Android app
-      run: |
-        cd android-mvn
-        mvn --batch-mode -Dcartridge.artifactId=retrodrawing -Dcartridge.groupId=com.github.msx80.omicron -Dcartridge.version=0.0.3 clean install android:apk
-    - name: Deploy retrodrawing Android App
-      uses: actions/upload-artifact@v4
-      with:
-        name: 'retrodrawing.apk'
-        path: android-mvn/target/retrodrawing.apk
     - name: Build snake Android app
       run: |
         cd android-mvn