CI: do not cross compile apps

Seems to run out of memory. Better switch to native arm runners

Author: jeroen

.github/workflows/base.yml

@@ -61,7 +61,7 @@ jobs:
       - name: Build opencpu/apps
         uses: docker/build-push-action@v6
         with:
-          platforms: linux/amd64,linux/arm64
+          platforms: linux/amd64
           context: docker/apps
           push: true
           tags: |