Manually install docker in workflow

.gitea/workflows/dockerbuild.yaml

@@ -13,6 +13,8 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v3
+      - name: Install Docker
+        run: curl -fsSL https://get.docker.com | sh
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v2
       - name: Login to DockerHub